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 It is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware.

Patches For Next.js 15.x, this issue is fixed in 15.2.3 For Next.js 14.x, this issue is fixed in 14.2.25 For Next.js 13.x, this issue is fixed in 13.5.9 For Next.js 12.x, this issue is fixed in 12.3.5 For Next.js 11.x, consult the below workaround.

Note: Next.js deployments hosted on Vercel are automatically protected against this vulnerability.

Workaround If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application.

Credits

- Allam Rachid (zhero;) - Allam Yasser (inzo)