CVE-2025-8291: Vulnerability in Python Software Foundation CPython
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.
AI Analysis
Technical Summary
The vulnerability in CPython's 'zipfile' module involves improper validation of the ZIP64 EOCD Locator record offset. Instead of using the offset to locate the ZIP64 EOCD record, the module assumed it was the previous record in the archive. This discrepancy could be exploited to craft ZIP archives that behave inconsistently between Python's 'zipfile' module and other ZIP tools. The fix maintains the original behavior but adds validation to confirm the offset is correct, preventing misuse of the offset field.
Potential Impact
This vulnerability may cause Python's 'zipfile' module to process specially crafted ZIP64 archives differently than other ZIP implementations, potentially leading to inconsistent handling of ZIP files. The impact is limited to integrity issues (low integrity impact) without confidentiality or availability effects. There are no known exploits in the wild.
Mitigation Recommendations
A remediation has been implemented that maintains the original behavior but adds validation to ensure the ZIP64 EOCD Locator offset matches the expected value. No additional action is required beyond applying the official fix when available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
CVE-2025-8291: Vulnerability in Python Software Foundation CPython
Description
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.
CVSS v3.1
Score 4.3medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in CPython's 'zipfile' module involves improper validation of the ZIP64 EOCD Locator record offset. Instead of using the offset to locate the ZIP64 EOCD record, the module assumed it was the previous record in the archive. This discrepancy could be exploited to craft ZIP archives that behave inconsistently between Python's 'zipfile' module and other ZIP tools. The fix maintains the original behavior but adds validation to confirm the offset is correct, preventing misuse of the offset field.
Potential Impact
This vulnerability may cause Python's 'zipfile' module to process specially crafted ZIP64 archives differently than other ZIP implementations, potentially leading to inconsistent handling of ZIP files. The impact is limited to integrity issues (low integrity impact) without confidentiality or availability effects. There are no known exploits in the wild.
Mitigation Recommendations
A remediation has been implemented that maintains the original behavior but adds validation to ensure the ZIP64 EOCD Locator offset matches the expected value. No additional action is required beyond applying the official fix when available. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:0123
- Cve Count
- 2
- Additional Cves
- ["CVE-2025-12084"]
Threat ID: 6a3da1cc4853345fc1823154
Added to database: 06/25/2026, 21:46:52 UTC
Last enriched: 07/31/2026, 00:50:48 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 29
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