CVE-2026-104871

Description

The Angular SSR is a server-rise rendering tool for Angular applications. Prior to versions 20.3.36, 21.2.23, and 22.1.7, the CommonEngine retrieveSSGPage prerendered-page retrieval logic in @angular/ssr/node, and in @angular/ssr for versions 17 through 18, accepts a relative request URL containing a backslash parent-traversal segment on Windows. The non-special resolve:// URL base preserves the backslash, path.join interprets it as a Windows separator, and the pagePath.startsWith(normalize(publicPath)) check incorrectly accepts a sibling output directory whose name shares the configured public-directory prefix. An unauthenticated requester can therefore retrieve a sibling prerendered HTML page when that page contains the Angular SSG marker. The issue is limited to Windows deployments that pass relative request URLs to CommonEngine.render, have a prefix-sharing sibling output directory, and contain qualifying prerendered Angular HTML; it does not provide arbitrary file read. This issue is fixed in versions 20.3.36, 21.2.23, and 22.1.7.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://github.com/angular/angular-cli/commit/645e41a47d21b7651837a4250de99af0509626e2
• https://github.com/angular/angular-cli/commit/70748ca8e76fe4b42798719410336119d943e755
• https://github.com/angular/angular-cli/commit/bb72145f9ab45aee29f523236b3a25cd0813a841
• https://github.com/angular/angular-cli/commit/c3e5982e49705f0f6a913cb94622b4c555d2d914
• https://github.com/angular/angular-cli/releases/tag/v20.3.36
• https://github.com/angular/angular-cli/releases/tag/v21.2.23
• https://github.com/angular/angular-cli/releases/tag/v22.1.7
• https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q

CWEs

CWE-22