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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 7.5Exploit: None knownExposed services: Not assessed

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
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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%
EPSS PROB
0.1%
EPSS %ILE
2nd
KEV
Not listed

Published

May 20, 2026

Last Modified

July 24, 2026

Advisory Details (1)

Auto-updated May 20, 2026
Patch available.
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 / EcosystemFix (by version range) / 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

(7 across 7 ecosystems)
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
unbound—
  • 1.16.2 up to 1.25.2-r0: fixed in 1.25.2-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
unbound—
  • 1.16.2 up to 1.25.2-r0: fixed in 1.25.2-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
unbound—
  • 1.16.2 up to 1.25.1-r0: fixed in 1.25.1-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.13.1-1 ... 1.25.2-1 (47 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.17.1-2 ... 1.26.1-1 (26 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.22.0-2 ... 1.26.0-2 (15 versions)
  • every version up to 1.26.1-0+deb13u1: fixed in 1.26.1-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
unbound1.22.0-2 ... 1.25.1-1 (9 versions)
  • every version up to 1.25.2-1: fixed in 1.25.2-1
—

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 7× in last 7d / 25× 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 312 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

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 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 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-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?
A fix for CVE-2026-40622 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-40622 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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