Package Instance

# Microsoft Security Advisory CVE-2025-21171 | .NET Remote Code Execution Vulnerability

## <a name="executive-summary"></a>Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

An attacker could exploit this vulnerability by sending a specially crafted request to the vulnerable web server.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/runtime/issues/111423

## <a name="mitigation-factors"></a>Mitigation factors

Microsoft has not identified any mitigating factors for this vulnerability.

## <a name="affected-software"></a>Affected software

* Any .NET 9.0 application running on .NET 9.0.0 or earlier.

## <a name="affected-packages"></a>Affected Packages

The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below

### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, < 9.0.1 | 9.0.1

## Advisory FAQ

### <a name="how-affected"></a>How do I know if I am affected?

If you have a runtime or SDK with a version listed, or an affected package listed in [affected software](#affected-packages) or [affected packages](#affected-software), you're exposed to the vulnerability.

### <a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET 9.0. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version.

* You can list the versions you have installed by running the `dotnet --info` command. You will see output like the following;

```
.NET SDK:
 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.3068a692
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.2
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/9.0.100/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: arm64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  9.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
```

* If you're using .NET 9.0, you should download and install .NET 9.0  Runtime or .NET 9.0.100 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

## Other Information

### Reporting Security Issues

If you have found a potential security issue in .NET 9.0 please email details to secure@microsoft.com. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at <https://aka.ms/corebounty>.

### Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2025-21171]( https://www.cve.org/CVERecord?id=CVE-2025-21171)

### Revisions

V1.0 (January 14, 2024): Advisory published.

# Microsoft Security Advisory CVE-2026-26127 – .NET Denial of Service Vulnerability

## Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 9.0 and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A denial of service vulnerability exists in .NET and Microsoft.Bcl.Memory due to an out-of-bounds read when decoding malformed Base64Url input.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/384

## CVSS Details

- **Version:** 3.1
- **Score:** 7.5
- **Vector:** `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C`
- **Severity:** High
- **Weakness:** CWE-129 (Improper Validation of Array Index); CWE-125 (Out-of-bounds Read)

## Affected Platforms

- **Platforms:** All
- **Architectures:** All

## Affected Products

### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, <= 9.0.13 | 9.0.14
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, <= 9.0.13 | 9.0.14

### <a name=".NET 10"></a>.NET 10
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 10.0.0, <= 10.0.3 | 10.0.4
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 10.0.0, <= 10.0.3 | 10.0.4

### <a name="Microsoft.Bcl.Memory 9.0.14"></a>Microsoft.Bcl.Memory 9.0.14
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.Bcl.Memory](https://www.nuget.org/packages/Microsoft.Bcl.Memory)                                                     | >= 9.0.0, <= 9.0.13 | 9.0.14

### <a name="Microsoft.Bcl.Memory 10.0.4"></a>Microsoft.Bcl.Memory 10.0.4
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.Bcl.Memory](https://www.nuget.org/packages/Microsoft.Bcl.Memory)                                                     | >= 10.0.0, <= 10.0.3 | 10.0.4

### <a name="how-fix"></a>How to fix the issue

To update the Microsoft.Bcl.Memory NuGet package, apply one of the following methods:

NuGet Package Manager UI in Visual Studio:
- Open the project in Visual Studio.
- Right-click on the project in Solution Explorer and select "Manage NuGet Packages..." or navigate to "Project > Manage NuGet Packages".
- In the NuGet Package Manager window, select the "Updates" tab. This tab lists packages with available updates from the configured package sources.
- Select the package(s) to update. A specific version can be chosen from the dropdown, or the latest available version can be selected.
- Click the "Update" button.

Using the NuGet Package Manager Console in Visual Studio:
- Open the project in Visual Studio.
- Navigate to "Tools > NuGet Package Manager > Package Manager Console".
- To update a specific package to its latest version, run the following Update-Package command:

```
Update-Package -Id Microsoft.Bcl.Memory
```

Using the .NET CLI (Command Line Interface):
- Open a terminal or command prompt in the project's directory.
- To update a specific package to its latest version, run the following command:

```
dotnet package update Microsoft.Bcl.Memory
```

Once the NuGet package reference has been updated, the application must be recompiled and redeployed. Additionally, it is recommended to update the runtime and/or SDKs, but unless the application targets .NET 9 or higher, updating the runtime and/or SDK is not a required step to patch this vulnerability.

## Other Information

### Reporting Security Issues

If a potential security issue has been found in a supported version of .NET, it should be reported to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

### Support

Questions about this issue can be asked on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. Questions can be asked in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2026-26127](https://www.cve.org/CVERecord?id=CVE-2026-26127)

### Revisions

V1.0 (March 10, 2026): Advisory published.

Microsoft Security Advisory CVE-2025-55248: .NET Information Disclosure Vulnerability
Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0 and .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A MITM (man in the middle) attacker may prevent use of TLS between client and SMTP server, forcing client to send data over unencrypted connection.

# Microsoft Security Advisory CVE-2025-30399 | .NET Remote Code Vulnerability

## <a name="executive-summary"></a>Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0 and .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

An attacker could exploit this vulnerability by placing files in particular locations, leading to unintended code execution.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/362

## <a name="mitigation-factors"></a>Mitigation factors

Microsoft has not identified any mitigating factors for this vulnerability.

## <a name="affected-software"></a>Affected software

* Any .NET 8.0 application running on .NET 8.0.16 or earlier.
* Any .NET 9.0 application running on .NET 9.0.5 or earlier.

## <a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below

### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, < =9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, < =9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, < =9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, <= 9.0.5 | 9.0.6
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, <= 9.0.5 | 9.0.6

### <a name=".NET 8"></a>.NET 8
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 8.0.0, <= 8.0.16 | 8.0.17
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 8.0.0, <= 8.0.16 | 8.0.17

## Advisory FAQ

### <a name="how-affected"></a>How do I know if I am affected?

If you have a runtime with a version listed, or an affected package listed in [affected software](#affected-packages) or [affected packages](#affected-software), you're exposed to the vulnerability.

### <a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET 9.0 or .NET 8.0, as appropriate. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version.

* You can list the versions you have installed by running the `dotnet --info` command. You will see output like the following;

```
.NET SDK:
 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.3068a692
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.2
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/9.0.100/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: arm64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  9.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
```

* If you're using .NET 8.0, you should download and install .NET 8.0.17  Runtime or .NET 8.0.314 SDK (for Visual Studio 2022 v17.10 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/8.0.
* If you're using .NET 9.0, you should download and install .NET 9.0.6  Runtime or .NET 9.0.107 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

## Other Information

### Reporting Security Issues

If you have found a potential security issue in .NET 9.0 or .NET 8.0, please email details to secure@microsoft.com. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at <https://aka.ms/corebounty>.

### Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2025-30399]( https://www.cve.org/CVERecord?id=CVE-2025-30399)

### Revisions

V1.0 (June 10, 2025): Advisory published.

Microsoft Security Advisory CVE-2026-32178 – .NET Spoofing Vulnerability
## Executive Summary: 

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0, .NET 9.0, and .NET 10.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

A vulnerability exists in System.Net.Mail where specially crafted data allows an unauthorized attacker to perform a spoofing attack over the network.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/12345

## CVSS Details

- **Version:** 3.1
- **Severity:** High
- **Score:** 7.5
- **Vector:** 7.5: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
- **Weakness:** CWE-138: Improper Neutralization of Special Elements

## Affected Platforms

- **Platforms:** All
- **Architectures:** All

## <a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected package versions listed below


### <a name=".NET 8"></a>.NET 8
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 8.0.0, <= 8.0.25 | 8.0.26
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 8.0.0, <= 8.0.25 | 8.0.26


### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, <= 9.0.14 | 9.0.15
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, <= 9.0.14 | 9.0.15

### <a name=".NET 10"></a>.NET 10
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 10.0.0, <= 10.0.5 | 10.0.6
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 10.0.0, <= 10.0.5 | 10.0.6

## Advisory FAQ

### <a name="how-affected"></a>How do I know if I am affected?

If using a package listed in [affected packages](#affected-packages), you're exposed to the vulnerability.

### <a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET 8.0, NET 9.0, or .NET 10.0, as appropriate. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version. You can list the versions you have installed by running the `dotnet --info` command.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

## Other Information

### Reporting Security Issues

If you have found a potential security issue in a supported version of .NET, please report it to the Microsoft Security Response Center (MSRC) via the [MSRC Researcher Portal](https://msrc.microsoft.com/report/vulnerability/new). Further information can be found in the MSRC [Report an Issue FAQ](https://www.microsoft.com/msrc/faqs-report-an-issue).

Security reports made through MSRC may qualify for the Microsoft .NET Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at https://aka.ms/corebounty.

### Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2026-32178]( https://www.cve.org/CVERecord?id=CVE-2026-32178)

### Acknowledgements

Ludvig Pedersen

### Revisions

V1.0 (April 14, 2026): Advisory published.

# Microsoft Security Advisory CVE-2025-21176 | .NET and Visual Studio Remote Code Execution Vulnerability

## <a name="executive-summary"></a>Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0 and .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

An attacker could exploit this vulnerability by loading a specially crafted file in Visual Studio.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/runtime/issues/111425

## <a name="mitigation-factors"></a>Mitigation factors

Microsoft has not identified any mitigating factors for this vulnerability.

## <a name="affected-software"></a>Affected software

* Any .NET 8.0 application running on .NET 8.0.11 or earlier.
* Any .NET 9.0 application running on .NET 9.0.0 or earlier.

## <a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below

### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, < 9.0.1 | 9.0.1

### <a name=".NET 8"></a>.NET 8
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 8.0.0, < 8.0.12 | 8.0.12

## Advisory FAQ

### <a name="how-affected"></a>How do I know if I am affected?

If you have a runtime or SDK with a version listed, or an affected package listed in [affected software](#affected-packages) or [affected packages](#affected-software), you're exposed to the vulnerability.

### <a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET 9.0 or .NET 8.0, as appropriate. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version.

* You can list the versions you have installed by running the `dotnet --info` command. You will see output like the following;

```
.NET SDK:
 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.3068a692
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.2
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/9.0.100/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: arm64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  9.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
```

* If you're using .NET 9.0, you should download and install .NET 9.0  Runtime or .NET 9.0.100 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

## Other Information

### Reporting Security Issues

If you have found a potential security issue in .NET 9.0 or .NET 8.0, please email details to secure@microsoft.com. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at <https://aka.ms/corebounty>.

### Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2025-21176]( https://www.cve.org/CVERecord?id=CVE-2025-21176)

### Revisions

V1.0 (January 14, 2024): Advisory published.

# Microsoft Security Advisory CVE-2025-21172 | .NET and Visual Studio Remote Code Execution Vulnerability

## <a name="executive-summary"></a>Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 8.0 and .NET 9.0. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

An attacker could exploit this vulnerability by loading a specially crafted file in Visual Studio.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/runtime/issues/111424.

## <a name="mitigation-factors"></a>Mitigation factors

Microsoft has not identified any mitigating factors for this vulnerability.

## <a name="affected-software"></a>Affected software

* Any .NET 8.0 application running on .NET 8.0.11 or earlier.
* Any .NET 9.0 application running on .NET 9.0.0 or earlier.

## <a name="affected-packages"></a>Affected Packages
The vulnerability affects any Microsoft .NET project if it uses any of affected packages versions listed below

### <a name=".NET 9"></a>.NET 9
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 9.0.0, < 9.0.1 | 9.0.1
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 9.0.0, < 9.0.1 | 9.0.1

### <a name=".NET 8"></a>.NET 8
Package name | Affected version | Patched version
------------ | ---------------- | -------------------------
[Microsoft.NetCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-arm64)           | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm)     | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-arm64) | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-musl-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-musl-x64)     | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.linux-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.linux-x64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.osx-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-arm64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.osx-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.osx-x64)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-arm](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-arm64)               | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x64)                   | >= 8.0.0, < 8.0.12 | 8.0.12
[Microsoft.NetCore.App.Runtime.win-x86](https://www.nuget.org/packages/Microsoft.NetCore.App.Runtime.win-x86)                   | >= 8.0.0, < 8.0.12 | 8.0.12

## Advisory FAQ

### <a name="how-affected"></a>How do I know if I am affected?

If you have a runtime or SDK with a version listed, or an affected package listed in [affected software](#affected-packages) or [affected packages](#affected-software), you're exposed to the vulnerability.

### <a name="how-fix"></a>How do I fix the issue?

1. To fix the issue please install the latest version of .NET 8.0 or .NET 9.0, as appropriate. If you have installed one or more .NET SDKs through Visual Studio, Visual Studio will prompt you to update Visual Studio, which will also update your .NET  SDKs.
2. If your application references the vulnerable package, update the package reference to the patched version.

* You can list the versions you have installed by running the `dotnet --info` command. You will see output like the following;

```
.NET SDK:
 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.3068a692
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.2
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /usr/local/share/dotnet/sdk/9.0.100/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: arm64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  9.0.100 [/usr/local/share/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  x64   [/usr/local/share/dotnet]
    registered at [/etc/dotnet/install_location_x64]

Environment variables:
  Not set

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
```

* If you're using .NET 9.0, you should download and install .NET 9.0  Runtime or .NET 9.0.100 SDK (for Visual Studio 2022 v17.12 latest Preview) from https://dotnet.microsoft.com/download/dotnet-core/9.0.

Once you have installed the updated runtime or SDK, restart your apps for the update to take effect.

Additionally, if you've deployed [self-contained applications](https://docs.microsoft.com/dotnet/core/deploying/#self-contained-deployments-scd) targeting any of the impacted versions, these applications are also vulnerable and must be recompiled and redeployed.

## Other Information

### Reporting Security Issues

If you have found a potential security issue in .NET 8.0 or .NET 9.0, please email details to secure@microsoft.com. Reports may qualify for the Microsoft .NET Core & .NET 5 Bounty. Details of the Microsoft .NET Bounty Program including terms and conditions are at <https://aka.ms/corebounty>.

### Support

You can ask questions about this issue on GitHub in the .NET GitHub organization. The main repos are located at https://github.com/dotnet/runtime. The Announcements repo (https://github.com/dotnet/Announcements) will contain this bulletin as an issue and will include a link to a discussion issue. You can ask questions in the linked discussion issue.

### Disclaimer

The information provided in this advisory is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

### External Links

[CVE-2025-21172]( https://www.cve.org/CVERecord?id=CVE-2025-21172)

### Revisions

V1.0 (January 14, 2024): Advisory published.