GHSA-8w7q-29mw-gf5c
Backstage: Improper validation of MkDocs theme configuration in TechDocs
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @backstage/plugin-techdocs-node | < 1.15.4 | 1.15.4 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in `mkdocs.yml` that cause arbitrary code execution during the documentation build process.
### Patches
Patched in `@backstage/plugin-techdocs-node` version `1.15.4`
### Workarounds
- Configure TechDocs with `techdocs.generator.runIn: 'docker'` instead of `'local'` to provide container isolation, though this does not fully mitigate the risk.
- Restrict write access to repositories registered in the Backstage catalog to trusted users.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c
- https://nvd.nist.gov/vuln/detail/CVE-2026-106509
- https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb
- https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d
- https://github.com/backstage/backstage
- https://github.com/backstage/backstage/releases/tag/v1.50.5
- https://github.com/backstage/backstage/releases/tag/v1.54.6