CVE-2026-31430

HIGHNVD 7.17.1—
EchelonGraph scoreMEDIUM confidence

Score 7.1 from GitHub Security Advisory (severity: HIGH) published 2026-04-20. NVD baseline CVSS 7.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In the Linux kernel, the following vulnerability has been resolved:

X.509: Fix out-of-bounds access when parsing extensions

Leo reports an out-of-bounds access when parsing a certificate with empty Basic Constraints or Key Usage extension because the first byte of the extension is read before checking its length. Fix it.

The bug can be triggered by an unprivileged user by submitting a specially crafted certificate to the kernel through the keyrings(7) API. Leo has demonstrated this with a proof-of-concept program responsibly disclosed off-list.

CVSS v3
7.1
EG Score
7.1(medium)
EG Risk
36(Track)
EG Risk 36/100SSVC: 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
Severity71% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
0%
KEV
Not listed

Published

April 20, 2026

Last Modified

May 21, 2026

Advisory Details (5)

Auto-updated Jun 14, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

X.509: Fix out-of-bounds access when parsing extensions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/d702c3408213bb12bd570bb97204d8340d141c51
generic🟡 PoC Available

X.509: Fix out-of-bounds access when parsing extensions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/7fb4dadc2734f4020d7543d688b8d49c8e569c61
generic🟡 PoC Available

X.509: Fix out-of-bounds access when parsing extensions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/672b526def1f94c1be8eb11b885b803da0d8c2f1
generic🟡 PoC Available

X.509: Fix out-of-bounds access when parsing extensions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/30ab358fad0c7daa1d282ec48089901b21b36a20
generic🟡 PoC Available

X.509: Fix out-of-bounds access when parsing extensions - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/206121294b9cf27f0589857f80d64f87e496ffb2

Vendor Advisories for CVE-2026-31430(2)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
linuxKernel @ 6.6.135—osv

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

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.85-1~bpo12+1 (17 versions)6.12.85-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.19~rc8-1~exp1 (127 versions)6.19.13-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(13)

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 4× in last 7d / 15× 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 196 total refreshes for this CVE.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-11 14:52 UTCEPSS rescore
  3. 2026-09-10 09:34 UTCEPSS rescore
  4. 2026-09-08 22:00 UTCEPSS rescore
  5. 2026-09-04 05:06 UTCEPSS rescore
  6. 2026-09-02 03:40 UTCOSV refresh
  7. 2026-09-01 13:53 UTCEPSS rescore
  8. 2026-08-28 21:41 UTCEPSS rescore
  9. 2026-08-26 14:46 UTCEPSS rescore
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-24 14:17 UTCEPSS rescore
  12. 2026-08-23 00:19 UTCEPSS rescore
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-20 22:55 UTCEPSS rescore
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-16 06:25 UTCVendor advisory
  17. 2026-08-16 06:25 UTCGHSA enrichment
  18. 2026-08-15 02:29 UTCVendor advisory
  19. 2026-08-15 02:29 UTCGHSA enrichment
  20. 2026-08-14 15:32 UTCVendor advisory
  21. 2026-08-14 15:32 UTCGHSA enrichment
  22. 2026-08-14 04:34 UTCVendor advisory
  23. 2026-08-14 04:34 UTCGHSA enrichment
  24. 2026-08-13 08:49 UTCVendor advisory
  25. 2026-08-13 08:49 UTCGHSA enrichment
Show 75 more
  1. 2026-08-12 18:44 UTCVendor advisory
  2. 2026-08-12 18:44 UTCGHSA enrichment
  3. 2026-08-11 16:55 UTCEG score recompute
  4. 2026-08-11 16:55 UTCVendor advisory
  5. 2026-08-11 16:55 UTCGHSA enrichment
  6. 2026-08-11 02:30 UTCVendor advisory
  7. 2026-08-11 02:30 UTCGHSA enrichment
  8. 2026-08-10 12:49 UTCVendor advisory
  9. 2026-08-10 12:49 UTCGHSA enrichment
  10. 2026-08-10 01:48 UTCVendor advisory
  11. 2026-08-10 01:48 UTCGHSA enrichment
  12. 2026-08-09 14:47 UTCVendor advisory
  13. 2026-08-09 14:47 UTCGHSA enrichment
  14. 2026-08-09 03:48 UTCVendor advisory
  15. 2026-08-09 03:48 UTCGHSA enrichment
  16. 2026-08-08 11:18 UTCVendor advisory
  17. 2026-08-08 11:18 UTCGHSA enrichment
  18. 2026-08-08 00:09 UTCVendor advisory
  19. 2026-08-08 00:09 UTCGHSA enrichment
  20. 2026-08-07 13:12 UTCVendor advisory
  21. 2026-08-07 13:11 UTCGHSA enrichment
  22. 2026-08-06 21:21 UTCVendor advisory
  23. 2026-08-06 21:21 UTCGHSA enrichment
  24. 2026-08-06 10:22 UTCVendor advisory
  25. 2026-08-06 10:22 UTCGHSA enrichment
  26. 2026-08-05 23:15 UTCEG score recompute
  27. 2026-08-05 23:15 UTCVendor advisory
  28. 2026-08-05 23:15 UTCGHSA enrichment
  29. 2026-08-05 19:17 UTCEPSS rescore
  30. 2026-08-04 15:10 UTCEPSS rescore
  31. 2026-08-03 21:27 UTCVendor advisory
  32. 2026-08-03 21:27 UTCGHSA enrichment
  33. 2026-08-02 23:54 UTCVendor advisory
  34. 2026-08-02 23:54 UTCGHSA enrichment
  35. 2026-08-02 12:56 UTCEG score recompute
  36. 2026-08-02 12:56 UTCVendor advisory
  37. 2026-08-02 12:56 UTCGHSA enrichment
  38. 2026-08-01 04:16 UTCEPSS rescore
  39. 2026-07-26 14:54 UTCEPSS rescore
  40. 2026-07-26 14:54 UTCEPSS rescore
  41. 2026-07-25 14:18 UTCEPSS rescore
  42. 2026-07-25 14:17 UTCEPSS rescore
  43. 2026-07-24 14:17 UTCEPSS rescore
  44. 2026-07-23 03:08 UTCEG score recompute
  45. 2026-07-22 14:08 UTCEPSS rescore
  46. 2026-07-22 14:08 UTCEPSS rescore
  47. 2026-07-20 07:04 UTCOSV refresh
  48. 2026-07-18 10:04 UTCEPSS rescore
  49. 2026-07-18 10:04 UTCEPSS rescore
  50. 2026-07-16 17:03 UTCEPSS rescore
  51. 2026-07-16 17:03 UTCEPSS rescore
  52. 2026-07-15 16:57 UTCEPSS rescore
  53. 2026-07-15 16:57 UTCEPSS rescore
  54. 2026-07-13 22:30 UTCEPSS rescore
  55. 2026-07-13 06:13 UTCEPSS rescore
  56. 2026-07-13 06:13 UTCEPSS rescore
  57. 2026-07-11 08:27 UTCEPSS rescore
  58. 2026-07-09 19:10 UTCEPSS rescore
  59. 2026-07-08 15:15 UTCEPSS rescore
  60. 2026-07-07 13:46 UTCEPSS rescore
  61. 2026-07-06 16:27 UTCEPSS rescore
  62. 2026-07-06 16:27 UTCEPSS rescore
  63. 2026-07-06 02:23 UTCEPSS rescore
  64. 2026-07-06 02:23 UTCEPSS rescore
  65. 2026-07-04 06:31 UTCEPSS rescore
  66. 2026-06-29 14:06 UTCEPSS rescore
  67. 2026-06-29 14:06 UTCEPSS rescore
  68. 2026-06-28 14:07 UTCEPSS rescore
  69. 2026-06-28 14:07 UTCEPSS rescore
  70. 2026-06-28 04:56 UTCEPSS rescore
  71. 2026-06-28 04:56 UTCEPSS rescore
  72. 2026-06-27 03:08 UTCEPSS rescore
  73. 2026-06-24 14:05 UTCEPSS rescore
  74. 2026-06-23 21:33 UTCEPSS rescore
  75. 2026-06-23 21:33 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-31430?
CVE-2026-31430 is a high vulnerability published on April 20, 2026. In the Linux kernel, the following vulnerability has been resolved: X.509: Fix out-of-bounds access when parsing extensions Leo reports an out-of-bounds access when parsing a certificate with empty Basic Constraints or Key Usage extension because the first byte of the extension is read before…
When was CVE-2026-31430 disclosed?
CVE-2026-31430 was first published in the National Vulnerability Database on April 20, 2026, with the most recent update on May 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-31430 actively exploited?
CVE-2026-31430 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 99.8% of all scored CVEs.
What is the CVSS score of CVE-2026-31430?
CVE-2026-31430 has a CVSS v3 base score of 7.1 (NVD).
How do I remediate CVE-2026-31430?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-31430, 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.

Dependency Blast Radius

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