Package Instance

Next.js has Unbounded Memory Consumption via PPR Resume Endpoint
A denial of service vulnerability exists in Next.js versions with Partial Prerendering (PPR) enabled when running in minimal mode. The PPR resume endpoint accepts unauthenticated POST requests with the `Next-Resume: 1` header and processes attacker-controlled postponed state data. Two closely related vulnerabilities allow an attacker to crash the server process through memory exhaustion:

1. **Unbounded request body buffering**: The server buffers the entire POST request body into memory using `Buffer.concat()` without enforcing any size limit, allowing arbitrarily large payloads to exhaust available memory.

2. **Unbounded decompression (zipbomb)**: The resume data cache is decompressed using `inflateSync()` without limiting the decompressed output size. A small compressed payload can expand to hundreds of megabytes or gigabytes, causing memory exhaustion.

Both attack vectors result in a fatal V8 out-of-memory error (`FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory`) causing the Node.js process to terminate. The zipbomb variant is particularly dangerous as it can bypass reverse proxy request size limits while still causing large memory allocation on the server.

To be affected, an application must run with `experimental.ppr: true` or `cacheComponents: true` configured along with the NEXT_PRIVATE_MINIMAL_MODE=1 environment variable.

Strongly consider upgrading to 15.6.0-canary.61 or 16.1.5 to reduce risk and prevent availability issues in Next applications.

Next.js: HTTP request smuggling in rewrites
## Summary
When Next.js rewrites proxy traffic to an external backend, a crafted `DELETE`/`OPTIONS` request using `Transfer-Encoding: chunked` could trigger request boundary disagreement between the proxy and backend. This could allow request smuggling through rewritten routes.

## Impact
An attacker could smuggle a second request to unintended backend routes (for example, internal/admin endpoints), bypassing assumptions that only the configured rewrite destination/path is reachable. This does not impact applications hosted on providers that handle rewrites at the CDN level, such as Vercel. 

## Patches
The vulnerability originated in an upstream library vendored by Next.js. It is fixed by updating that dependency’s behavior so `content-length: 0` is added only when both `content-length` and `transfer-encoding` are absent, and `transfer-encoding` is no longer removed in that code path.

## Workarounds
If upgrade is not immediately possible:
- Block chunked `DELETE`/`OPTIONS` requests on rewritten routes at your edge/proxy.
- Enforce authentication/authorization on backend routes per our [security guidance](https://nextjs.org/docs/app/guides/data-security).

Next.js: null origin can bypass Server Actions CSRF checks
## Summary
`origin: null` was treated as a "missing" origin during Server Action CSRF validation. As a result, requests from opaque contexts (such as sandboxed iframes) could bypass origin verification instead of being validated as cross-origin requests.

## Impact
An attacker could induce a victim browser to submit Server Actions from a sandboxed context, potentially executing state-changing actions with victim credentials (CSRF).

## Patches
Fixed by treating `'null'` as an explicit origin value and enforcing host/origin checks unless `'null'` is explicitly allowlisted in `experimental.serverActions.allowedOrigins`.  

## Workarounds
If upgrade is not immediately possible:
- Add CSRF tokens for sensitive Server Actions.
- Prefer `SameSite=Strict` on sensitive auth cookies.
- Do not allow `'null'` in `serverActions.allowedOrigins` unless intentionally required and additionally protected.

Next.js: Unbounded postponed resume buffering can lead to DoS
## Summary
A request containing the `next-resume: 1` header (corresponding with a PPR resume request) would buffer request bodies without consistently enforcing `maxPostponedStateSize` in certain setups. The previous mitigation protected minimal-mode deployments, but equivalent non-minimal deployments remained vulnerable to the same unbounded postponed resume-body buffering behavior.

## Impact
In applications using the App Router with Partial Prerendering capability enabled (via `experimental.ppr` or `cacheComponents`), an attacker could send oversized `next-resume` POST payloads that were buffered without consistent size enforcement in non-minimal deployments, causing excessive memory usage and potential denial of service.

## Patches
Fixed by enforcing size limits across all postponed-body buffering paths and erroring when limits are exceeded.  

## Workarounds
If upgrade is not immediately possible:
- Block requests containing the `next-resume` header, as this is never valid to be sent from an untrusted client.

Next.js: Unbounded next/image disk cache growth can exhaust storage
## Summary
The default Next.js image optimization disk cache (`/_next/image`) did not have a configurable upper bound, allowing unbounded cache growth.

## Impact
An attacker could generate many unique image-optimization variants and exhaust disk space, causing denial of service. Note that this does not impact platforms that have their own image optimization capabilities, such as Vercel.

## Patches
Fixed by adding an LRU-backed disk cache with `images.maximumDiskCacheSize`, including eviction of least-recently-used entries when the limit is exceeded. Setting `maximumDiskCacheSize: 0` disables disk caching. 

## Workarounds
If upgrade is not immediately possible:
- Periodically clean `.next/cache/images`.
- Reduce variant cardinality (e.g., tighten values for `images.localPatterns`, `images.remotePatterns`, and `images.qualities`)

Next.js HTTP request deserialization can lead to DoS when using insecure React Server Components
A vulnerability affects certain React Server Components packages for versions 19.0.x, 19.1.x, and 19.2.x and frameworks that use the affected packages, including Next.js 13.x, 14.x, 15.x, and 16.x using the App Router. The issue is tracked upstream as [CVE-2026-23864](https://github.com/facebook/react/security/advisories/GHSA-83fc-fqcc-2hmg).

A specially crafted HTTP request can be sent to any App Router Server Function endpoint that, when deserialized, may trigger excessive CPU usage, out-of-memory exceptions, or server crashes. This can result in denial of service in unpatched environments.

Next.js: null origin can bypass dev HMR websocket CSRF checks
## Summary
In `next dev`, cross-site protections for internal development endpoints could treat `Origin: null` as a bypass case even when [`allowedDevOrigins`](https://nextjs.org/docs/app/api-reference/config/next-config-js/allowedDevOrigins) is configured. This could allow privacy-sensitive or opaque browser contexts, such as sandboxed documents, to access privileged internal dev-server functionality unexpectedly.

## Impact
If a developer visits attacker-controlled content while running an affected `next dev` server with [`allowedDevOrigins`](https://nextjs.org/docs/app/api-reference/config/next-config-js/allowedDevOrigins) configured, attacker-controlled browser code may be able to connect to internal development endpoints and interact with sensitive dev-server functionality that should have remained blocked.

This issue affects development mode only. It does not affect `next start`, and it does not expose internal debugging functionality to the network by default.

## Patches
Fixed by validating `Origin: null` through the same cross-site origin-allowance checks used for other origins on internal development endpoints.

## Workarounds
If upgrade is not immediately possible:
- Do not expose `next dev` to untrusted networks.
- If you use [`allowedDevOrigins`](https://nextjs.org/docs/app/api-reference/config/next-config-js/allowedDevOrigins), reject requests and websocket upgrades with `Origin: null` for internal dev endpoints at your proxy.

Next.js self-hosted applications vulnerable to DoS via Image Optimizer remotePatterns configuration
A DoS vulnerability exists in self-hosted Next.js applications that have `remotePatterns` configured for the Image Optimizer. The image optimization endpoint (`/_next/image`) loads external images entirely into memory without enforcing a maximum size limit, allowing an attacker to cause out-of-memory conditions by requesting optimization of arbitrarily large images. This vulnerability requires that `remotePatterns` is configured to allow image optimization from external domains and that the attacker can serve or control a large image on an allowed domain.

Strongly consider upgrading to 15.5.10 and 16.1.5 to reduce risk and prevent availability issues in Next applications.

Next has a Denial of Service with Server Components - Incomplete Fix Follow-Up
It was discovered that the fix for [CVE-2025-55184](https://github.com/advisories/GHSA-2m3v-v2m8-q956) in React Server Components was incomplete and did not fully mitigate denial-of-service conditions across all payload types.  As a result, certain crafted inputs could still trigger excessive resource consumption.

This vulnerability affects React versions 19.0.2, 19.1.3, and 19.2.2, as well as frameworks that bundle or depend on these versions, including Next.js 13.x, 14.x, 15.x, and 16.x when using the App Router. The issue is tracked upstream as [CVE-2025-67779](https://www.cve.org/CVERecord?id=CVE-2025-67779).

A malicious actor can send a specially crafted HTTP request to a Server Function endpoint that, when deserialized, causes the React Server Components runtime to enter an infinite loop. This can lead to sustained CPU consumption and cause the affected server process to become unresponsive, resulting in a denial-of-service condition in unpatched environments.