CVE-2025-8291 MEDIUM

CVE-2025-8291: ZIP64 End of Central Directory (EOCD) Locator record offset not checked

Vendor Python Software Foundation
Product CPython
Published October 7, 2025
Last update April 21, 2026
View on NVD All CVEs

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

October 7, 2025 CVE published
April 21, 2026 Record updated