Path Traversal in Python Software Foundation Cpython

CVE-2026-11940

tarfile.extractall() with the 'data' or 'tar' filter could be bypassed by a crafted archive where a hardlink references a symlink stored at a deeper name than the hardlink itself.  The extraction fallback validated the symlink at it's archived location but recreated it at the hardlink's shallower path, letting a relative target the filter judged contained escape the destination directory.  This allowed a malicious tar archive to create a symlink pointing outside the destination, enabling out-of-destination file reads or writes. This was an incomplete fix of CVE-2025-4330.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.007 (53.0th percentile) — read the EPSS interpretation.