GHSA-6jr7-99pf-8vgf @backstage/plugin-techdocs-node vulnerable to arbitrary code execution via MkDocs hooks

• npm @backstage/plugin-techdocs-node: >= 1.14.0, < 1.14.1 → fixed in 1.14.1 • npm @backstage/plugin-techdocs-node: < 1.13.11 → fixed in 1.13.11

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 vulnerability, as the CLI uses the same vulnerable `@backstage/plugin-techdocs-node` package. References MkDocs Hooks Documentation MkDocs 1.4 Release Notes TechDocs Architecture