CVE-2026-34604: @tinacms/graphql's `FilesystemBridge` Path Validation Can Be Bypassed via Symlinks or Junctions

@tinacms/graphql uses string-based path containment checks in FilesystemBridge:

• path.resolve(path.join(baseDir, filepath))
• startsWith(resolvedBase + path.sep)

That blocks plain ../ traversal, but it does not resolve symlink or junction targets. If a symlink/junction already exists under the allowed content root, a path like content/posts/pivot/owned.md is still considered “inside” the base even though the real filesystem target can be outside it.

As a result, FilesystemBridge.get(), put(), delete(), and glob() can operate on files outside the intended root.