@backstage/plugin-techdocs-node vulnerable to arbitrary code execution via MkDocs hooks
Date: 2026-02
Affected: npm/@backstage/plugin-techdocs-node, npm/@backstage/plugin-techdocs-node
Attack vector: rce
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-25153
CWE: CWE-94
CVSS: 7.7 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L)

### Impact When TechDocs is configured with `runIn: local`, a malicious actor who can submit or modify a repository's `mkdocs.yml` file can execute arbitrary Python code on the TechDocs build server via MkDocs hooks configuration. ### Patches Upgrade to `@backstage/plugin-techdocs-node` version 1.13.11, 1.14.1 or later. The fix introduces an allowlist of supported MkDocs configuration keys. Unsupported configuration keys (including `hooks`) are now removed from `mkdocs.yml` before running the generator, with a warning logged to indicate which keys were removed. **Note**: Users of `@techdocs/cli` should also upgrade to the latest version, which includes the fixed `@backstage/plugin-techdocs-node` dependency. ### Workarounds If you cannot upgrade immediately: 1. Use Docker mode with restricted access: Configure TechDocs with `runIn: docker` instead of `runIn: local`. This provides container isolation, though it does not fully mitigate the risk. 2. Restrict repository access: Limit who can modify `mkdocs.yml` files in repositories that TechDocs processes. Only allow trusted contributors. 3. Manual review: Implement PR review requirements for changes to `mkdocs.yml` files to detect malicious `hooks` configurations before they are merged. 4. Downgrade MkDocs: Use MkDocs < 1.4.0 (e.g., 1.3.1) which does not support hooks. Note: This may limit access to newer MkDocs features. **Note**: Building documentation in CI/CD pipelines using `@techdocs/cli` does not mitigate this vul


Mitigations:

Architectural layers (MAESTRO):