CVE-2026-29509: Wummel Patool

Medium severity, CVSS 5.4. EPSS: 0.4% chance of exploitation in the next 30 days.

Patool before 4.0.5 contains a path traversal vulnerability in the safe_extract() function in patoolib/programs/py_tarfile.py when running on Python before 3.12, where the is_within_directory() helper uses os.path.commonprefix() for character-level string comparison instead of path-level comparison, allowing a crafted archive member path to bypass the containment check. Attackers can supply a malicious archive with specially crafted member paths to write arbitrary files.

Affected products

• Wummel Patool: before 4.0.5 (fixed in 4.0.5)

Published 2026-06-26. Last modified 2026-07-14.