ZIP64 End of Central Directory (EOCD) Locator record offset not checked

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-8291
StatePUBLISHED
AssignerPSF
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-10-07 18:16:00 UTC
Updated2026-10-08 22:10:00 UTC
DescriptionThe '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.

Risk And Classification

Primary CVSS: v3.1 4.3 MEDIUM from [email protected]

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

EPSS: 0.004660000 probability, percentile 0.384640000 (date 2026-10-10)

Problem Types: CWE-1285 | CWE-1285 CWE-1285 Improper Validation of Specified Index, Position, or Offset in Input

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
3.1CNACVSS4.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Python Software Foundation CPython affected 3.9.24 python Not specified
CNA Python Software Foundation CPython affected 3.10.0 3.10.19 python Not specified
CNA Python Software Foundation CPython affected 3.11.0 3.11.14 python Not specified
CNA Python Software Foundation CPython affected 3.12.0 3.12.12 python Not specified
CNA Python Software Foundation CPython affected 3.13.0 3.13.10 python Not specified
CNA Python Software Foundation CPython affected 3.14.0 3.14.1 python Not specified

References

ReferenceSourceLinkTags
github.com/python/cpython/commit/d11e69d6203080e3ec450446bfed0516727b85c3 [email protected] github.com
github.com/python/cpython/commit/76437ac248ad8ca44e9bf697b02b1e2241df2196 [email protected] github.com
github.com/python/cpython/pull/139702 [email protected] github.com
github.com/google/security-research/security/advisories/GHSA-hhv7-p4pg-wm6p 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
github.com/psf/advisory-database/blob/main/advisories/python/PSF-2025-12... 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
github.com/python/cpython/commit/bca11ae7d575d87ed93f5dd6a313be6246e3e388 [email protected] github.com
github.com/python/cpython/commit/1d29afb0d6218aa8fb5e1e4a6133a4778d89bb46 [email protected] github.com
github.com/python/cpython/issues/139700 [email protected] github.com
github.com/python/cpython/commit/162997bb70e067668c039700141770687bc8f267 [email protected] github.com
github.com/python/cpython/commit/333d4a6f4967d3ace91492a39ededbcf3faa76a6 [email protected] github.com
mail.python.org/archives/list/[email protected]/thread/QECOPWMTH4V... [email protected] mail.python.org
github.com/python/cpython/commit/8392b2f0d35678407d9ce7d95655a5b77de161b4 [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Caleb Brown (Google) (en)

CNA: Serhiy Storchaka (en)

CNA: Seth Larson (en)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report