Impact
There is a denial of service vulnerability in React Server Components.
React recommends updating immediately.
The vulnerability exists in versions 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1 of:
- react-server-dom-webpack - react-server-dom-parcel - react-server-dom-turbopack
These issues are present in the patches published last week.
Patches
Fixes were back ported to versions 19.0.2, 19.1.3, and 19.2.2.
If you are using any of the above packages please upgrade to any of the fixed versions immediately.
If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability.
References
See the blog post for more information and upgrade instructions.
Impact
It was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. Refer to CVE-2026-44575 for further details.
References
- CVE CVE-2026-44575
Impact
App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check.
Fix
We now include App Router transport variants when generating middleware matchers, so middleware protections are applied consistently to those requests as well as to the normal page URL.
Workarounds
If you cannot upgrade immediately, enforce authorization in the underlying route or page logic instead of relying solely on middleware.
Impact
There is an unauthenticated remote code execution vulnerability in React Server Components.
We recommend upgrading immediately.
The vulnerability is present in versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0 of: react-server-dom-webpack react-server-dom-parcel react-server-dom-turbopack
Patches
A fix was introduced in versions 19.0.1, 19.1.2, and 19.2.1. If you are using any of the above packages please upgrade to any of the fixed versions immediately.
If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability.
References
See the blog post for more information and upgrade instructions.
Impact
There is a source code exposure vulnerability in React Server Components.
React recommends updating immediately.
The vulnerability exists in versions 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1 of:
- react-server-dom-webpack - react-server-dom-parcel - react-server-dom-turbopack
These issues are present in the patches published last week.
Patches
Fixes were back ported to versions 19.0.2, 19.1.3, and 19.2.2.
If you are using any of the above packages please upgrade to any of the fixed versions immediately.
If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability.
References
See the blog post for more information and upgrade instructions.
Impact
It was found that the fix to address CVE-2025-55184 in React Server Components was incomplete and does not prevent a denial of service attack in a specific case.
We recommend updating immediately.
The vulnerability exists in versions 19.0.2, 19.1.3, and 19.2.2 of:
- react-server-dom-webpack - react-server-dom-parcel - react-server-dom-turbopack
These issues are present in the patches published on December 11th, 2025.
Patches
Fixes were back ported to versions 19.0.3, 19.1.4, and 19.2.3.
If you are using any of the above packages please upgrade to any of the fixed versions immediately.
If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability.
References
See the blog post for more information and upgrade instructions.