A pre-authentication denial of service vulnerability exists in React Server Components versions 19.0.0, 19.0.1 19.1.0, 19.1.1, 19.1.2, 19.2.0 and 19.2.1, including the following packages: react-server-dom-parcel, react-server-dom-turbopack, and react-server-dom-webpack. The vulnerable code unsafely deserializes payloads from HTTP requests to Server Function endpoints, which can cause an infinite loop that hangs the server process and may prevent future HTTP requests from being served.

Affected: npm: react-server-dom-parcel, npm: react-server-dom-turbopack, npm: react-server-dom-webpack

## 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](https://www.npmjs.com/package/react-server-dom-webpack) - [react-server-dom-parcel](https://www.npmjs.com/package/react-server-dom-parcel) - [react-server-dom-turbopack](https://www.npmjs.com/package/react-server-dom-turbopack?activeTab=readme)

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](https://react.dev/blog/2025/12/11/denial-of-service-and-source-code-exposure-in-react-server-components) for more information and upgrade instructions.

Ein Angreifer kann mehrere Schwachstellen in Vercel Next.js und React Server Components ausnutzen, um Informationen offenzulegen und um einen Denial of Service Angriff durchzuführen.