Multiple denial of service vulnerabilities exist in React Server Components, affecting the following packages: react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack.

The vulnerabilities are triggered by sending specially crafted HTTP requests to Server Function endpoints, and could lead to server crashes, out-of-memory exceptions or excessive CPU usage; depending on the vulnerable code path being exercised, the application configuration and application code.

Strongly consider upgrading to the latest package versions to reduce risk and prevent availability issues in applications using React Server Components.

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

## Impact

It was found that the fixes to address DoS in React Server Components were incomplete and we found multiple denial of service vulnerabilities still exist in React Server Components.

We recommend updating immediately.

The vulnerability exists in versions 19.0.0, 19.0.1, 19.0.2, 19.0.3, 19.1.0, 19.1.1, 19.1.2, 19.1.3, 19.1.4, 19.2.0, 19.2.1, 19.2.2, 19.2.3 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)

The vulnerabilities are triggered by sending specially crafted HTTP requests to Server Function endpoints, and could lead to server crashes, out-of-memory exceptions or excessive CPU usage; depending on the vulnerable code path being exercised, the application configuration and application code.

## Patches

Fixes were back ported to versions 19.0.4, 19.1.5, and 19.2.4.

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-…

jose4j: jose4j: Denial of Service via malicious JSON Web Encryption (JWE) token compression next: Next.js Server-Side Request Forgery in Server Actions golang: net/url: Memory exhaustion in query parameter parsing in net/url crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate axios: Axios: Server-Side Request Forgery and proxy bypass due to improper hostname normalization crypto/tls: crypto/tls: Incorrect certificate validation during TLS session resumption io.vertx/vertx-core: static handler component cache can be manipulated to deny the access to static files lodash: lodash: Arbitrary code execution via untrusted input in template imports react-server-dom-webpack: react-server-dom-parcel: reactreact-server-dom-turbopack: React Server Components: Denial of Service via specially crafted HTTP requests next.js: Next.js: Unbounded next/image disk cache growth can exhaust storage io.netty/netty-codec-http: Netty: Request smuggling via incorrect parsing of HTTP/1.1 chunked transfer encoding extension values netty: Netty: Denial of Service via HTTP/2 CONTINUATION frame flood axios: Axios: Remote Code Execution via Prototype Pollution escalation

Ein Angreifer kann mehrere Schwachstellen in Vercel Next.js ausnutzen, um einen Denial of Service Angriff durchzuführen.