Headline
GHSA-j893-m93w-jwjw: fast-filesystem-mcp has a Path Traversal vulnerability
fast-filesystem-mcp version 3.4.0 contains a critical path traversal vulnerability in its file operation tools including fast_read_file. This vulnerability arises from improper path validation that fails to resolve symbolic links to their actual physical paths. The safePath and isPathAllowed functions use path.resolve() which does not handle symlinks, allowing attackers to bypass directory access restrictions by creating symlinks within allowed directories that point to restricted system paths. When these symlinks are accessed through valid path references, the validation checks are circumvented, enabling access to unauthorized files.
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2025-67364
fast-filesystem-mcp has a Path Traversal vulnerability
High severity GitHub Reviewed Published Jan 7, 2026 to the GitHub Advisory Database • Updated Jan 8, 2026
Package
npm fast-filesystem-mcp (npm)
Affected versions
<= 3.4.0
fast-filesystem-mcp version 3.4.0 contains a critical path traversal vulnerability in its file operation tools including fast_read_file. This vulnerability arises from improper path validation that fails to resolve symbolic links to their actual physical paths. The safePath and isPathAllowed functions use path.resolve() which does not handle symlinks, allowing attackers to bypass directory access restrictions by creating symlinks within allowed directories that point to restricted system paths. When these symlinks are accessed through valid path references, the validation checks are circumvented, enabling access to unauthorized files.
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-67364
- efforthye/fast-filesystem-mcp#10
- https://github.com/efforthye/fast-filesystem-mcp
Published to the GitHub Advisory Database
Jan 7, 2026