CVE-2026-25152: @backstage/plugin-techdocs-node vulnerable to possible Path Traversal in TechDocs Local Generator

A path traversal vulnerability in the TechDocs local generator allows attackers to read arbitrary files from the host filesystem when Backstage is configured with techdocs.generator.runIn: local.

When processing documentation from untrusted sources, symlinks within the docs directory are followed by MkDocs during the build process. File contents are embedded into generated HTML and exposed to users who can view the documentation.