Executive brief
A vulnerability in the Angular Service Worker library could allow unauthorized access to sensitive user data. The component, which helps web applications work offline and load faster, fails to respect security settings that should block automatic redirects to private pages. If a user visits a specially crafted link while logged into a site using this library, their private account information or session cookies could be exposed to parts of the application that should not have access to them.
Technical details
A vulnerability exists in the @angular/service-worker package where the internal helper function `AssetGroup.newRequestWithMetadata()` fails to preserve the `redirect` policy of a Request object during reconstruction. When the Service Worker intercepts a request configured with a strict policy (e.g., `redirect: 'error'`), it strips this configuration and reverts to the browser's default 'follow' strategy. An attacker can exploit this 'Confused Deputy' scenario if a public route matched by the Service Worker redirects to a sensitive, session-restricted same-origin endpoint. If a victim has an active session, the Service Worker will transparently follow the redirect and return protected data to the client-side code, bypassing developer-defined security boundaries. The issue is fixed in versions 19.2.23, 20.3.22, 21.2.15, and 22.0.0-rc.2.
Affected products
- Angular angular/service-worker < 19.2.23, >= 19.0.0-next.0; < 20.3.22, >= 20.0.0-next.0; < 21.2.15, >= 21.0.0-next.0; < 22.0.0-rc.2, >= 22.0.0-next.0; <= 18.2.14
Timeline
- 2026-03-06: other: Initial pull request submitted to fix the issue
- 2026-03-18: patched: Fix merged into Angular main branch
- 2026-05-28: advisory: GitHub Security Advisory published
- 2026-06-22: disclosed: CVE published to NVD