CVE-2026-104871
Angular SSR: Path Traversal to Sibling Directories in CommonEngine on Windows
- State
- Published
- Severity
- 6.3 Medium
- Published
- Oct 2, 2026
- Updated
- Oct 2, 2026
- Reserved
- Oct 2, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Products
| Product | Versions |
|---|---|
angular-cliangular |
|
References
- https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q
- 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
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