CVE-2026-11940
HIGHtarfile extraction filter bypass allows escaping the destination directory
Title source: cnaDescription
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.
References (8)
Core 8
Core References
Patch patch
https://github.com/python/cpython/pull/151559
Vendor Advisory vendor-advisory
https://mail.python.org/archives/list/[email protected]/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/
Issue Tracking issue-tracking
https://github.com/python/cpython/issues/151558
Scores
CVSS v4
7.8
EPSS
0.0063
EPSS Percentile
46.8%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-22
CWE-59
Status
published
Products (3)
Python Software Foundation/CPython
< 3.15.0
Python Software Foundation/CPython
< 3.15.0b4
Python Software Foundation/CPython
< 3.16.0
Published
Jun 23, 2026
Tracked Since
Jun 23, 2026