Vulnerability · Published Oct 2, 2026 · Assigned by GitHub_M
CVE-2026-104871Angular SSR: Path Traversal to Sibling Directories in CommonEngine on Windows
Medium 6.3
In plain English
A medium-severity path traversal in angular-cli from angular. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @angular/ssr | 22.1.7 | GHSA-7g7c-h8rr-7p6q |
| npm | @angular/ssr | 21.2.23 | GHSA-7g7c-h8rr-7p6q |
| npm | @angular/ssr | 20.3.36 | GHSA-7g7c-h8rr-7p6q |
| npm | @angular/ssr | no fix listed | GHSA-7g7c-h8rr-7p6q |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| angular | angular-cli | < 20.3.36>= 21.0.0, < 21.2.23>= 22.0.0, < 22.1.7 |
Weakness: CWE-22 · Vector: 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
References
- https://github.com/angular/angular-cli/security/advisories/GHSA-7g7c-h8rr-7p6q x_refsource_CONFIRM
- https://github.com/angular/angular-cli/commit/645e41a47d21b7651837a4250de99af0509626e2 x_refsource_MISC
- https://github.com/angular/angular-cli/commit/70748ca8e76fe4b42798719410336119d943e755 x_refsource_MISC
- https://github.com/angular/angular-cli/commit/bb72145f9ab45aee29f523236b3a25cd0813a841 x_refsource_MISC
- https://github.com/angular/angular-cli/commit/c3e5982e49705f0f6a913cb94622b4c555d2d914 x_refsource_MISC
- https://github.com/angular/angular-cli/releases/tag/v20.3.36 x_refsource_MISC
- https://github.com/angular/angular-cli/releases/tag/v21.2.23 x_refsource_MISC
- https://github.com/angular/angular-cli/releases/tag/v22.1.7 x_refsource_MISC