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.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 7.8NVD modified 2026-10-26 11:10
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 10
- 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/[email protected]/thread/LD6QIISNQFQYOIEPJNEUIPV7S3V76FZH/