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
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 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)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 24, 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(7)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuunbound-host (1.24.2-1ubuntu2.1) @ resolute2026-08-23ubuntu
redhatrhcos-4.22.9.8.202608130832-02026-08-18redhat
redhatunbound-0:1.16.2-5.12.el8_102026-07-09redhat
redhatunbound-0:1.24.2-3.el9_8.22026-07-08redhat
redhatunbound-0:1.24.2-7.el10_2.22026-07-07redhat
redhatunbound-main-1.25.1-1.hum12026-05-23redhat

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

(5 across 5 ecosystems)
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
unbound—1.25.1-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
unbound1.13.1-1 ... 1.25.2-1 (47 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
unbound1.17.1-2 ... 1.25.2-1 (23 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
unbound1.22.0-2, 1.22.0-2+deb13u1, 1.22.0-2+deb13u21.22.0-2+deb13u3—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
unbound1.22.0-2 ... 1.25.0-1 (8 versions)1.25.1-1—

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 14× in last 7d / 99× 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 275 total refreshes for this CVE.

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

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 July 24, 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 0% probability of exploitation in the next 30 days, which ranks it in the top 96.8% of all scored CVEs.
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.

Dependency Blast Radius

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