A pre-authentication remote code execution vulnerability exists in React Server Components versions 19.0.0, 19.1.0, 19.1.1, and 19.2.0 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.
React applications which rendered to HTML using the ReactDOMServer API were not escaping user-supplied attribute names at render-time. That lack of escaping could lead to a cross-site scripting vulnerability. This issue affected minor releases 16.0.x, 16.1.x, 16.2.x, 16.3.x, and 16.4.x. It was fixed in 16.0.1, 16.1.2, 16.2.1, 16.3.3, and 16.4.2.