CVE-2026-87910tarfile hardlink fallback ignores custom extraction filter rejection via None
Updated under an hour ago ()
Does this affect you?
It affects Python Software Foundation CPython. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
When tarfile extracts a link on a system that doesn't support links, it falls back to extracting a member from the archive. In this case, the filter function is run twice: once for the extracted member, and once with name set to the location of the link. For one of the calls, the return value was ignored. Instead, the member should be skipped if either call returns None.
- CVSS
- 5.7 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-22, CWE-59
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- PSF
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 3, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Python Software Foundation CPython python_software_foundation:cpython (from the name) | before 3.10.22; from 3.11.0 before 3.11.17; from 3.12.0 before 3.12.15; from 3.13.0 before 3.13.16; from 3.15.0a1 before 3.15.0rc3 | CNA record |
References
- https://mail.python.org/archives/list/security-announce@python.org/thread/57TBTLL2W6APMZR3A25B2YV7GL3EPTDJ/vendor-advisory
- https://github.com/python/cpython/pull/157266patch
- https://github.com/python/cpython/issues/157265issue-tracking
- https://github.com/python/cpython/commit/d9565e54b1fc6d63c5be9afd58114499128fa57bpatch
- https://github.com/python/cpython/commit/fb2f0bbc3b35264f09cc2cb2934b7987527a6bc2patch
- https://github.com/python/cpython/commit/9c17bace90f88dfba6d0e2fe23c8e7ae35f83955patch
- https://github.com/python/cpython/commit/764fd0af8d9e19d3684a58d2e58bf770f0605036patch
- https://github.com/python/cpython/commit/2eb0c2f1dc71847731b6ab30aebefd058d482a7fpatch
- https://github.com/python/cpython/commit/c1f106d240c4ffcb3608ed0a20e8aba6c865f6d3patch
- https://github.com/python/cpython/commit/3105a3498aaf681ce128cf5baf83c2e5574267c5patch
- https://github.com/python/cpython/commit/a4919937a4e1e69a0d178909c6f20557eca5d1d0patch
- http://www.openwall.com/lists/oss-security/2026/09/11/8
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.