Vulnerability in Python Software Foundation Cpython
CVE-2025-8291
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.
EPSS: 0.004 (28.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N.
Affected products
- Python Software Foundation Cpython — versions 3.10.0, 3.14.0, 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cna@python.org (patch)
- cna@python.org (vendor-advisory)
- cna@python.org (issue-tracking)
- cna@python.org (patch)
- cna@python.org (patch)
- cna@python.org (patch)
- cna@python.org (patch)
- cna@python.org (patch)
- cna@python.org (patch)
- cna@python.org (patch)
Frequently asked questions
- What is CVE-2025-8291?
- CVE-2025-8291 is a medium-severity vulnerability in Python Software Foundation Cpython, classified under CWE-1285. CVSS score: 4.3/10. Published 2025-10-07.
- How severe is CVE-2025-8291?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2025-8291 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.