Path traversal in CPython - CVE-2026-11940

Vulnerability identifier: #VU153035

CSH Severity: High

CVSS v4: 7.8 [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]

CVE-ID: CVE-2026-11940

CWE-ID: CWE-22

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to 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. A remote attacker can use malicious tar archive to create a symlink pointing outside the destination, enabling out-of-destination file reads or writes.

CPython
Anolis OS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Maximo Application Suite - Edge Data Collector
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
python3 (Red Hat package)
python3-test
python3-tkinter
python3-libs
python3-idle
python3-devel
platform-python-devel
platform-python-debug
platform-python
python3.9 (Red Hat package)
python3.12 (Red Hat package)

Install updates from vendor's website.

CPython - addressed in versions 3.10.21, 3.11.16, 3.12.14, 3.13.15, 3.14.7
Maximo Application Suite - Edge Data Collector - addressed in versions 9.0.25, 9.1.15, 9.2.4
python3 (Red Hat package) - addressed in versions 3.6.8-47.el8_6.15, 3.6.8-78.el8_10
python3-test - update to 3.6.8-78.0.1
python3-tkinter - update to 3.6.8-78.0.1
python3-libs - update to 3.6.8-78.0.1
python3-idle - update to 3.6.8-78.0.1
python3-devel - update to 3.6.8-78.0.1
platform-python-devel - update to 3.6.8-78.0.1
platform-python-debug - update to 3.6.8-78.0.1
platform-python - update to 3.6.8-78.0.1
python3.9 (Red Hat package) - update to 3.9.25-7.el9_8.3
python3.12 (Red Hat package) - addressed in versions 3.12.1-4.el9_4.15, 3.12.9-1.el9_6.10, 3.12.9-2.el10_0.11, 3.12.14-1.el10_2

• https://github.com/python/cpython/commit/0f852b3f07dd8e71e40326a51c02afbf16a42cc5
• https://github.com/python/cpython/commit/27dd970bf6b17ebca7c8ed486a40ab043ed7af8f
• https://github.com/python/cpython/commit/672825e2f36a57e173959b0d9d409d4560dab8df
• https://github.com/python/cpython/commit/771d12dda5140313db0ac550292987975651bbde
• https://github.com/python/cpython/commit/79c06bd5c6afa3c440d50faf7ee1b147c8832b4c
• https://github.com/python/cpython/commit/be13e86f6b9788a6f4d0419dffef72cbae5865c9
• https://github.com/python/cpython/commit/e5fdbd8d5aa923bd9111b112ea73bd6ec7c47877
• https://github.com/python/cpython/issues/151558
• https://github.com/python/cpython/pull/151559
• https://mail.python.org/archives/list/security-announce@python.org/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/

• Path traversal in cpython
• Multiple vulnerabilities in IBM Edge Data Collector
• Anolis OS update for python3
• Red Hat Enterprise Linux 9 update for python3.9
• Red Hat Enterprise Linux 8 update for python3
• Red Hat Enterprise Linux 10 update for python3.12
• Red Hat Enterprise Linux 9 update for python3.12
• Red Hat Enterprise Linux 10 update for python3.12
• Red Hat Enterprise Linux 9 update for python3.12
• Red Hat Enterprise Linux 8 update for python3