Description
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.
Severity (CVSS)
| Base score | 7.8 |
|---|---|
| Severity | High |
| Version | CVSS 4.0 |
| 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 |
| Provided by | CNA |
Weaknesses
- CWE-22 — CWE-22
- CWE-59 — CWE-59
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Python Software Foundation | CPython | 0 to <3.15.0 |
References
- https://github.com/python/cpython/pull/151559 (patch)
- https://mail.python.org/archives/list/security-announce@python.org/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/ (vendor-advisory)
- https://github.com/python/cpython/issues/151558 (issue-tracking)
- https://github.com/python/cpython/commit/27dd970bf6b17ebca7c8ed486a40ab043ed7af8f (patch)
- https://github.com/python/cpython/commit/672825e2f36a57e173959b0d9d409d4560dab8df (patch)
- https://github.com/python/cpython/commit/771d12dda5140313db0ac550292987975651bbde (patch)
- https://github.com/python/cpython/commit/79c06bd5c6afa3c440d50faf7ee1b147c8832b4c (patch)
Generated from the official CVE List on 24 Jun 2026 09:35 UTC.