Package Instance

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 has a Denial of Service with Server Components
A vulnerability affects certain React Server Components packages for versions 19.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-2026-23869](https://github.com/facebook/react/security/advisories/GHSA-479c-33wc-g2pg). You can read more about this advisory our [this changelog](https://vercel.com/changelog/summary-of-cve-2026-23869).

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

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 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.