CVE-2026-42009

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-18. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
67.8%
KEV
Not listed

Published

May 18, 2026

Last Modified

July 8, 2026

Advisory Details (2)

Auto-updated May 18, 2026
Patch available. Sources: redhat.
redhat

2467279 – (CVE-2026-42009) CVE-2026-42009 gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability

https://bugzilla.redhat.com/show_bug.cgi?id=2467279
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-42009

Vendor Advisories for CVE-2026-42009(19)

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

Patch Availability(12)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatlibtasn1-0:4.13-3.el8_6.22026-06-29redhat
redhatgnutls-0:3.8.3-4.el9_4.62026-06-29redhat
redhatlibtasn1-0:4.13-4.el8_8.12026-06-29redhat
ubuntulibgnutls30t64 (3.8.12-2ubuntu1.1) @ resolute2026-06-29ubuntu
redhatgnutls-0:3.8.3-6.el9_6.42026-06-25redhat
redhatdiscovery/discovery-ui-rhel9:17821669522026-06-24redhat
redhatrhui5/rhua-rhel9:17815257392026-06-16redhat
redhatgnutls-0:3.8.9-9.el10_0.192026-06-16redhat
redhatgnutls-0:3.6.16-8.el8_10.62026-05-26redhat
redhatgnutls-0:3.8.10-4.el10_22026-05-26redhat
redhatgnutls-0:3.8.10-4.el9_82026-05-26redhat
redhatgnutls-main-3.8.13-1.hum12026-05-02redhat

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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 9× in last 7d / 91× 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 200 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42009?
CVE-2026-42009 is a high vulnerability published on May 18, 2026. A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This…
When was CVE-2026-42009 disclosed?
CVE-2026-42009 was first published in the National Vulnerability Database on May 18, 2026, with the most recent update on July 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42009 actively exploited?
CVE-2026-42009 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 67.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42009?
CVE-2026-42009 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-42009?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42009, 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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