CVE-2026-54264: Exposure of Sensitive Information to an Unauthorized Actor

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.1, 21.2.17, and 20.3.25, an information disclosure vulnerability exists in the @angular/service-worker package of the Angular framework. When the Service Worker fetches assets, it preserves metadata (such as headers) from the original request. However, on cross-origin redirects, the Service Worker fails to strip sensitive headers, violating the Fetch redirect algorithm. This allows a remote attacker to obtain sensitive credentials (e.g., Authorization tokens, Proxy-Authorization credentials, or session cookies) by triggering a cross-origin redirect to an untrusted external origin. This vulnerability is fixed in 22.0.1, 21.2.17, and 20.3.25.