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.
Scoring
- Severity
- HIGH
- CVSS base score
- 7.8
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
- EPSS probability
- 0.75%
- CWE
- CWE-22, CWE-59
- Published
- 2026-06-23
- Last modified
- 2026-08-13
Affected products
- Python Software Foundation CPython
- Python Software Foundation CPython
- Python Software Foundation CPython
- Python Software Foundation CPython
- Python Software Foundation CPython
- Python Software Foundation CPython
Weakness type
Related vulnerabilities
- CVE-2026-15019 — Direct Download for WooCommerce <= 1.19 - Unauthenticated Arbitrary File Read via 'file_id' Path Segment
- CVE-2026-18386 — WP BackItUp Community Edition <= 2.1.0 - Authenticated (Administrator+) Path Traversal to Arbitrary File Read via 'backup_file' Parameter
- CVE-2026-88069 — Path traversal in Pandora archive extractor allows arbitrary file writes outside the extraction directory in pandora analysis
- CVE-2026-53956 — Rattler vulnerable to package cache path traversal via conda package build string
- CVE-2026-86775 — knowns before 0.30.0 Path Traversal via Document API
- CVE-2026-86099 — Chainlit through 2.12.0 Path Traversal via socket.io sessionId
- CVE-2026-78485 — Dell SCG 5.0 Appliance versions prior to 5.36.00.16 and Dell SCG 5.0 Application versions prior to...
- CVE-2026-19729 — Keycloak-services: keycloak-services: incomplete fix for arbitrary filesystem path probing via keystore parameters