ZIP Archive Mismanagement in Python Zipfile Module
CVE-2025-8291

4.3MEDIUM

Key Information:

Vendor

Python Software Foundation

Status
Cpython
Vendor
CVE Published:
7 October 2025

What is CVE-2025-8291?

The Python 'zipfile' module contains a vulnerability due to its failure to validate the ZIP64 End of Central Directory (EOCD) Locator record offset. This oversight can lead to discrepancies in how ZIP archives are processed, allowing attackers to create modified ZIP files that behave incorrectly when handled by the 'zipfile' module versus other implementations. While recent patches have been enacted to remedy this issue, they merely ensure that the offset specified in the ZIP64 EOCD Locator record conforms to expected standards, thereby mitigating potential exploitation.

Affected Version(s)

CPython 0 <= 3.14.0

References

https://github.com/python/cpython/pull/139702
patch
https://mail.python.org/archives/list/security-announce@p...
vendor-advisory
https://github.com/python/cpython/issues/139700
issue-tracking

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Caleb Brown (Google)
Serhiy Storchaka
Seth Larson
JSON
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CVE-2025-8291 : ZIP Archive Mismanagement in Python Zipfile Module