CVE-2026-40622

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory 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: 0%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost) zone and be able to query a vulnerable Unbound. A single client NS query can cause Unbound to overwrite the cached expired parent-side referral NS rrset with the child-side apex NS rrset and essentially extend the ghost domain window by up to one cached TTL configured value ('cache-max-ttl'). In configurations where 'harden-referral-path: yes' is used (non-default configuration), no client NS query is required since Unbound implicitly performs that query. Unbound 1.25.1 contains a patch with a fix that does not allow extension of TTLs for (parent) NS records regardless of their trust.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
6.8%
KEV
Not listed

Published

May 20, 2026

Last Modified

May 26, 2026

Advisory Details (1)

Auto-updated May 20, 2026
No patch confirmed yet.
generic
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-40622.txt

Vendor Advisories for CVE-2026-40622(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
ubuntuunbound-host (1.13.1-1ubuntu5.15) @ jammy2026-06-29ubuntu

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 / 89× 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 191 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-40622?
CVE-2026-40622 is a high vulnerability published on May 20, 2026. NLnet Labs Unbound 1.16.2 up to and including version 1.25.0 has a vulnerability of the 'ghost domain names' family of attacks that could extend the ghost domain window by up to one cached TTL configured value. Similar to other 'ghost domain names' attacks, an adversary needs to control a (ghost)…
When was CVE-2026-40622 disclosed?
CVE-2026-40622 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on May 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40622 actively exploited?
CVE-2026-40622 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 6.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40622?
CVE-2026-40622 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-40622?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40622, 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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