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

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.

Published: 2025-10-07 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-8291 is rated Low Risk (24.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-8291

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-03-05 0.17% 0.07% -0.09%
2 2026-02-06 0.07% 0.17% +0.10%
3 2025-10-16 0.07%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-8291

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 1.4 [email protected]

Weakness enumeration for CVE-2025-8291

OS Trackers for CVE-2025-8291

vendor priority summary link
debian end-of-life CVE-2025-8291 end-of-life priority: Debian including 6 source packages (jython, pypy3, python3.11, python3.13, python3.14, python3.9), 17 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10, open 7. https://security-tracker.debian.org/tracker/CVE-2025-8291
redhat medium https://access.redhat.com/security/cve/CVE-2025-8291
suse low CVE-2025-8291 severity low: SUSE including 631 source package names (0.0.17-1.18:libpython3_11-1_0-3.11.14-150600.3.38.1, 0.0.17-1.18:python311-base-3.11.14-150600.3.38.1, …), 2252 product×package rows across 339 product lines (Container bci/spack, Container containers/lmcache-lmstack-router, … (339 product lines)): Fixed 2007, Known Affected 231, First Fixed 14. https://www.suse.com/security/cve/CVE-2025-8291/
ubuntu medium CVE-2025-8291 medium priority: Ubuntu including 12 source packages (python2.7, python3.10, …), 72 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 41, needs-triage 16, released 14, ignored 1. https://ubuntu.com/security/CVE-2025-8291

Affected software / configurations for CVE-2025-8291

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-8291

URL Tags
https://github.com/python/cpython/commit/162997bb70e067668c039700141770687bc8f267
https://github.com/python/cpython/commit/1d29afb0d6218aa8fb5e1e4a6133a4778d89bb46
https://github.com/python/cpython/commit/333d4a6f4967d3ace91492a39ededbcf3faa76a6
https://github.com/python/cpython/commit/76437ac248ad8ca44e9bf697b02b1e2241df2196
https://github.com/python/cpython/commit/8392b2f0d35678407d9ce7d95655a5b77de161b4
https://github.com/python/cpython/commit/bca11ae7d575d87ed93f5dd6a313be6246e3e388
https://github.com/python/cpython/commit/d11e69d6203080e3ec450446bfed0516727b85c3
https://github.com/python/cpython/issues/139700
https://github.com/python/cpython/pull/139702
https://mail.python.org/archives/list/[email protected]/thread/QECOPWMTH4VPPJAXAH2BGTA4XADOP62G/
https://github.com/google/security-research/security/advisories/GHSA-hhv7-p4pg-wm6p
https://github.com/psf/advisory-database/blob/main/advisories/python/PSF-2025-12.json
cvelogic Threat Intelligence