CVE-2026-29509

Patool < 4.0.5 Path Traversal via safe_extract() Function

State: Published
Severity: 5.3 Medium
Published: Jun 26, 2026
Updated: Jul 14, 2026
Reserved: Mar 4, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	5.3 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N	VulnCheck
3.1	5.4 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N	VulnCheck

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

Product	Versions
patoolwummel	before 4.0.5Affected

References

https://github.com/wummel/patool/releases/tag/4.0.5patch
https://github.com/wummel/patool/blob/main/doc/changelog.txtrelease-notes
https://www.vulncheck.com/advisories/patool-path-traversal-via-safe-extract-functionthird-party-advisory

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