CVE-2026-42944

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-20. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
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.

NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be enabled for the vulnerability to be exploited. An adversary who can query Unbound can exploit the vulnerability by attaching multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options to the query. A flaw in the size calculation of the EDNS field truncates the correct value which allows the encoder to overflow the available space when writing. Those two combined lead to a heap overflow write of Unbound controlled data and eventually a crash. Unbound 1.25.1 contains a patch with a fix to de-duplicate the EDNS options and a fix to prevent truncation of the EDNS field size calculation.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
54.1%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 15, 2026

Advisory Details (1)

Auto-updated May 20, 2026
No patch confirmed yet.
generic
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-42944.txt

Vendor Advisories for CVE-2026-42944(4)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuunbound-host (1.24.2-1ubuntu2.1) @ resolute2026-06-29ubuntu
redhatunbound-0:1.16.2-5.11.el8_102026-06-08redhat
redhatunbound-0:1.24.2-3.el9_8.12026-06-08redhat
redhatunbound-0:1.24.2-7.el10_2.12026-06-04redhat
redhatunbound-main-1.25.1-0.1.hum12026-05-20redhat

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(2)

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 8× in last 7d / 46× 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 163 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42944?
CVE-2026-42944 is a high vulnerability published on May 20, 2026. NLnet Labs Unbound 1.14.0 up to and including version 1.25.0 has a vulnerability that results in heap overflow when encoding multiple NSID and/or DNS Cookie EDNS and/or EDNS Padding options in the reply packet. The relevant options ('nsid', 'answer-cookie', 'pad-responses' (default)) need to be…
When was CVE-2026-42944 disclosed?
CVE-2026-42944 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42944 actively exploited?
CVE-2026-42944 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 54.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-42944?
CVE-2026-42944 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-42944?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42944, 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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