CVE-2025-8291

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

Score 4.3 from GitHub Security Advisory published 2025-10-07. a secondary CVSS source baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: Elevated riskExposed: 0

A fix is available — apply it.

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
4.3
EG Score
4.3(medium)
EG Risk
35(Track)
EG Risk 35/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
KEV
Not listed

Published

October 7, 2025

Last Modified

July 31, 2026

Advisory Details (10)

Auto-updated Jul 30, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit, github_pr.
github_commit

commit d11e69d62030 (python/cpython)

Fix landed in python/cpython commit d11e69d62030 — awaiting tagged release

https://github.com/python/cpython/commit/d11e69d6203080e3ec450446bfed0516727b85c3
github_commit

commit bca11ae7d575 (python/cpython)

Fix landed in python/cpython commit bca11ae7d575 — awaiting tagged release

https://github.com/python/cpython/commit/bca11ae7d575d87ed93f5dd6a313be6246e3e388
github_commit

commit 8392b2f0d356 (python/cpython)

Fix landed in python/cpython commit 8392b2f0d356 — awaiting tagged release

https://github.com/python/cpython/commit/8392b2f0d35678407d9ce7d95655a5b77de161b4
github_commit

commit 76437ac248ad (python/cpython)

Fix landed in python/cpython commit 76437ac248ad — awaiting tagged release

https://github.com/python/cpython/commit/76437ac248ad8ca44e9bf697b02b1e2241df2196
github_commit

commit 1d29afb0d621 (python/cpython)

Fix landed in python/cpython commit 1d29afb0d621 — awaiting tagged release

https://github.com/python/cpython/commit/1d29afb0d6218aa8fb5e1e4a6133a4778d89bb46
github_commit

commit 333d4a6f4967 (python/cpython)

Fix landed in python/cpython commit 333d4a6f4967 — awaiting tagged release

https://github.com/python/cpython/commit/333d4a6f4967d3ace91492a39ededbcf3faa76a6
github_commit

commit 162997bb70e0 (python/cpython)

Fix landed in python/cpython commit 162997bb70e0 — awaiting tagged release

https://github.com/python/cpython/commit/162997bb70e067668c039700141770687bc8f267
generic

Add more consistency checks in zipfile · Issue #139700 · python/cpython · GitHub

https://github.com/python/cpython/issues/139700
generic

Mailman 3 [CVE-2025-8291] ZIP64 End of Central Directory (EOCD) Locator record offset not checked - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/QECOPWMTH4VPPJAXAH2BGTA4XADOP62G/
github_pr

gh-139700: Check consistency of the zip64 end of central directory record

Fix merged in python/cpython PR #139702 on 2025-10-07 — awaiting tagged release

https://github.com/python/cpython/pull/139702

Vendor Advisories for CVE-2025-8291(16)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(18)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupython3.13-venv (3.13.7-1ubuntu0.1) @ questing2026-07-31ubuntu
ubuntupython3.5-venv (3.5.2-2ubuntu0~16.04.4~14.04.1+esm8) @ trusty2026-07-31ubuntu
redhatpython3-12-main-3.12.13-3.hum12026-04-17redhat
redhatpython3-11-main-3.11.15-4.hum12026-04-17redhat
redhatpython3-14-main-3.14.4-1.hum12026-04-11redhat
redhatpython3-13-main-3.13.13-1.hum12026-04-10redhat
redhatrhceph/rhceph-7-rhel9:17695084552026-02-03redhat
redhatrhceph/rhceph-8-rhel9:17695123832026-02-02redhat
redhatrhui5/rhua-rhel9:17683770122026-01-15redhat
redhatpython3.12-0:3.12.1-4.el9_4.82026-01-08redhat
redhatpython3.12-0:3.12.9-1.el9_6.32026-01-08redhat
redhatdiscovery/discovery-ui-rhel9:17679045732026-01-08redhat
redhatpython3.12-0:3.12.9-2.el10_0.42026-01-08redhat
redhatpython3.12-0:3.12.12-1.el8_102026-01-06redhat
redhatpython3.12-0:3.12.12-1.el10_12025-12-22redhat
redhatpython3.12-0:3.12.12-1.el9_72025-12-18redhat
redhatpython39-devel:3.9-8100020251126112422.d47b87a42025-12-18redhat
redhatpython3.9-0:3.9.25-2.el9_72025-12-18redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(13 across 4 ecosystems)
Debian:14(4)
PackageVulnerable rangeFixed inDependents
jython2.7.3+repack1-1——
pypy37.3.19+dfsg-2, 7.3.20+dfsg-1, 7.3.20+dfsg-2, 7.3.20+dfsg-3, 7.3.20+dfsg-47.3.21+dfsg-1—
python3.133.13.5-2, 3.13.6-1, 3.13.7-1, 3.13.8-1, 3.13.9-13.13.11-1—
python3.143.14.0-1 ... 3.14.0~rc3-1 (10 versions)3.14.0-3—
Debian:11(3)
PackageVulnerable rangeFixed inDependents
jython2.7.2+repack1-3, 2.7.2+repack1-4, 2.7.2+repack1-5, 2.7.3+repack1-1——
pypy37.3.5+dfsg-2, 7.3.5+dfsg-2+deb11u1, 7.3.5+dfsg-2+deb11u2, 7.3.5+dfsg-2+deb11u3, 7.3.5+dfsg-2+deb11u47.3.5+dfsg-2+deb11u5—
python3.93.9.2-1, 3.9.2-1+deb11u1, 3.9.2-1+deb11u2, 3.9.2-1+deb11u33.9.2-1+deb11u4—
Debian:12(3)
PackageVulnerable rangeFixed inDependents
jython2.7.3+repack1-1——
pypy37.3.11+dfsg-2 ... 7.3.23+dfsg-1 (29 versions)——
python3.113.11.2-6 ... 3.11.2-6+deb12u6 (7 versions)3.11.2-6+deb12u7—
Debian:13(3)
PackageVulnerable rangeFixed inDependents
jython2.7.3+repack1-1——
pypy37.3.19+dfsg-2 ... 7.3.23+dfsg-1 (11 versions)——
python3.133.13.5-23.13.5-2+deb13u1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 6× in last 7d / 28× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 169 total refreshes for this CVE.

  1. 2026-08-30 01:21 UTCEPSS rescore
  2. 2026-08-28 21:40 UTCEPSS rescore
  3. 2026-08-27 14:24 UTCEPSS rescore
  4. 2026-08-26 14:45 UTCEPSS rescore
  5. 2026-08-25 13:48 UTCEPSS rescore
  6. 2026-08-24 14:16 UTCEPSS rescore
  7. 2026-08-23 00:18 UTCEPSS rescore
  8. 2026-08-21 23:48 UTCEPSS rescore
  9. 2026-08-20 22:55 UTCEPSS rescore
  10. 2026-08-19 17:03 UTCEPSS rescore
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 13:46 UTCEPSS rescore
  13. 2026-08-16 14:55 UTCEPSS rescore
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 21:07 UTCOSV refresh
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-13 22:00 UTCEPSS rescore
  18. 2026-08-12 13:50 UTCEPSS rescore
  19. 2026-08-11 13:42 UTCEPSS rescore
  20. 2026-08-10 23:59 UTCEPSS rescore
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-08 16:36 UTCEPSS rescore
  23. 2026-08-07 16:27 UTCEPSS rescore
  24. 2026-08-06 13:46 UTCEPSS rescore
  25. 2026-08-05 19:17 UTCEPSS rescore
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  1. 2026-08-04 10:37 UTCEPSS rescore
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  3. 2026-08-02 02:26 UTCEPSS rescore
  4. 2026-08-01 04:15 UTCEPSS rescore
  5. 2026-07-31 14:25 UTCEG score recompute
  6. 2026-07-31 14:25 UTCVendor advisory
  7. 2026-07-31 14:25 UTCGHSA enrichment
  8. 2026-07-31 14:09 UTCEG score recompute
  9. 2026-07-31 14:09 UTCVendor advisory
  10. 2026-07-31 14:09 UTCGHSA enrichment
  11. 2026-07-30 23:20 UTCEG score recompute
  12. 2026-07-30 23:20 UTCVendor advisory
  13. 2026-07-30 23:20 UTCGHSA enrichment
  14. 2026-07-30 22:21 UTCEG score recompute
  15. 2026-07-30 22:21 UTCVendor advisory
  16. 2026-07-30 22:21 UTCGHSA enrichment
  17. 2026-07-30 16:27 UTCEPSS rescore
  18. 2026-07-30 01:30 UTCEPSS rescore
  19. 2026-07-27 14:13 UTCEPSS rescore
  20. 2026-07-27 10:09 UTCOSV refresh
  21. 2026-07-26 14:54 UTCEPSS rescore
  22. 2026-07-26 14:54 UTCEPSS rescore
  23. 2026-07-25 14:17 UTCEPSS rescore
  24. 2026-07-25 14:17 UTCEPSS rescore
  25. 2026-07-24 14:17 UTCEPSS rescore
  26. 2026-07-23 14:18 UTCEPSS rescore
  27. 2026-07-23 14:18 UTCEPSS rescore
  28. 2026-07-23 03:03 UTCEG score recompute
  29. 2026-07-22 14:08 UTCEPSS rescore
  30. 2026-07-21 15:24 UTCEPSS rescore
  31. 2026-07-20 17:08 UTCEPSS rescore
  32. 2026-07-19 14:30 UTCEPSS rescore
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  34. 2026-07-19 02:28 UTCEPSS rescore
  35. 2026-07-19 02:28 UTCEPSS rescore
  36. 2026-07-18 10:04 UTCEPSS rescore
  37. 2026-07-18 10:04 UTCEPSS rescore
  38. 2026-07-16 17:02 UTCEPSS rescore
  39. 2026-07-16 17:02 UTCEPSS rescore
  40. 2026-07-15 16:57 UTCEPSS rescore
  41. 2026-07-15 16:57 UTCEPSS rescore
  42. 2026-07-15 02:00 UTCEPSS rescore
  43. 2026-07-15 01:59 UTCEPSS rescore
  44. 2026-07-13 06:12 UTCEPSS rescore
  45. 2026-07-12 05:46 UTCEPSS rescore
  46. 2026-07-12 05:46 UTCEPSS rescore
  47. 2026-07-11 08:27 UTCEPSS rescore
  48. 2026-07-11 08:27 UTCEPSS rescore
  49. 2026-07-10 04:53 UTCOSV refresh
  50. 2026-07-09 19:10 UTCEPSS rescore
  51. 2026-07-08 15:15 UTCEPSS rescore
  52. 2026-07-07 13:46 UTCEPSS rescore
  53. 2026-07-06 16:27 UTCEPSS rescore
  54. 2026-07-06 02:23 UTCEPSS rescore
  55. 2026-07-05 02:30 UTCEPSS rescore
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  57. 2026-07-04 06:31 UTCEPSS rescore
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  59. 2026-07-01 15:06 UTCEPSS rescore
  60. 2026-06-30 23:22 UTCEPSS rescore
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  62. 2026-06-29 14:06 UTCEPSS rescore
  63. 2026-06-29 14:06 UTCEPSS rescore
  64. 2026-06-28 14:07 UTCEPSS rescore
  65. 2026-06-28 14:07 UTCEPSS rescore
  66. 2026-06-28 04:56 UTCEPSS rescore
  67. 2026-06-28 04:56 UTCEPSS rescore
  68. 2026-06-27 03:08 UTCEPSS rescore
  69. 2026-06-25 13:49 UTCEPSS rescore
  70. 2026-06-25 13:49 UTCEPSS rescore
  71. 2026-06-24 14:05 UTCEPSS rescore
  72. 2026-06-24 14:04 UTCEPSS rescore
  73. 2026-06-23 21:32 UTCEPSS rescore
  74. 2026-06-22 14:25 UTCEPSS rescore
  75. 2026-06-22 14:25 UTCEPSS rescore

Frequently asked(5)

What is CVE-2025-8291?
CVE-2025-8291 is a medium vulnerability published on October 7, 2025. 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…
When was CVE-2025-8291 disclosed?
CVE-2025-8291 was first published in the National Vulnerability Database on October 7, 2025, with the most recent update on July 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-8291 actively exploited?
CVE-2025-8291 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 71.9% of all scored CVEs.
What is the CVSS score of CVE-2025-8291?
CVE-2025-8291 has a CVSS v3 base score of 4.3 (NVD).
How do I remediate CVE-2025-8291?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-8291, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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