CVE-2025-8291
ZIP64 End of Central Directory (EOCD) Locator record offset not checked
CVSS Score
4.3
EPSS Score
0.1%
EPSS Percentile
30th
The 'zipfile' module would not check the validity of the ZIP64 End of Central Directory (EOCD) Locator record offset value would not be used to locate the ZIP64 EOCD record, instead the ZIP64 EOCD record would be assumed to be the previous record in the ZIP archive. This could be abused to create ZIP archives that are handled differently by the 'zipfile' module compared to other ZIP implementations. Remediation maintains this behavior, but checks that the offset specified in the ZIP64 EOCD Locator record matches the expected value.
| Vendor | python software foundation |
| Product | cpython |
| Published | Oct 7, 2025 |
| Last Updated | Apr 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
Python Software Foundation / CPython
0 < 3.10.19 3.11.0 < 3.11.14 3.12.0 < 3.12.12 3.13.0 < 3.13.10 3.14.0 < 3.14.1
References
github.com: https://github.com/python/cpython/pull/139702 mail.python.org: https://mail.python.org/archives/list/[email protected]/thread/QECOPWMTH4VPPJAXAH2BGTA4XADOP62G/ github.com: https://github.com/python/cpython/issues/139700 github.com: https://github.com/python/cpython/commit/162997bb70e067668c039700141770687bc8f267 github.com: https://github.com/python/cpython/commit/333d4a6f4967d3ace91492a39ededbcf3faa76a6 github.com: https://github.com/python/cpython/commit/1d29afb0d6218aa8fb5e1e4a6133a4778d89bb46 github.com: https://github.com/python/cpython/commit/76437ac248ad8ca44e9bf697b02b1e2241df2196 github.com: https://github.com/python/cpython/commit/8392b2f0d35678407d9ce7d95655a5b77de161b4 github.com: https://github.com/python/cpython/commit/bca11ae7d575d87ed93f5dd6a313be6246e3e388 github.com: https://github.com/python/cpython/commit/d11e69d6203080e3ec450446bfed0516727b85c3 github.com: https://github.com/psf/advisory-database/blob/main/advisories/python/PSF-2025-12.json github.com: https://github.com/google/security-research/security/advisories/GHSA-hhv7-p4pg-wm6p
Credits
🔍 Caleb Brown (Google) Serhiy Storchaka Seth Larson