# CVE-2026-29509: patool: Patool before 4.0.5 contains a path traversal vulnerability in the safe_extract() function in patoolib/programs/py_ta...

CVE-2026-29509 is fixed in patool on 1 platform, first by DEBIAN-CVE-2026-29509, released June 28, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-29509
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 26, 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | patool Debian 13.5 (trixie) | 4.0.0-1+deb13u1 | [DEBIAN-CVE-2026-29509](https://patchblox.com/security/data/fix/linux/debian-cve-2026-29509.md) | Jun 28, 2026 |
| Linux | patool Debian 14 | 4.0.5-0.1 | [DEBIAN-CVE-2026-29509](https://patchblox.com/security/data/fix/linux/debian-cve-2026-29509.md) | Jun 28, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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