CVE-2026-5947

HIGHNVD 5.97.5▲
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-20. NVD baseline CVSS 5.9; sources differ by 1.6.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.9Exploit: None knownExposed: 0

A fix is available — apply it.

Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.

CVSS v3
5.9
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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
69%
KEV
Not listed

Published

May 20, 2026

Last Modified

July 23, 2026

Advisory Details (3)

Auto-updated Jun 6, 2026
No patch confirmed yet.
generic

CVE-2026-5947: SIG(0) validation during query flood may lead to undefined behavior

https://kb.isc.org/docs/cve-2026-5947
generic

Index of /isc/bind9/9.21.22

https://downloads.isc.org/isc/bind9/9.21.22
generic

Index of /isc/bind9/9.20.23

https://downloads.isc.org/isc/bind9/9.20.23

Vendor Advisories for CVE-2026-5947(3)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntubind9-utils (1:9.20.18-1ubuntu2.1) @ resolute2026-07-26ubuntu
redhatbind-main-9.18.48-1.1.hum12026-04-10redhat

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(3)

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 18× in last 7d / 57× 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 179 total refreshes for this CVE.

  1. 2026-07-27 14:14 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 08:15 UTCEG score recompute
  5. 2026-07-26 08:15 UTCVendor advisory
  6. 2026-07-26 08:14 UTCGHSA enrichment
  7. 2026-07-25 14:18 UTCEPSS rescore
  8. 2026-07-25 14:18 UTCEPSS rescore
  9. 2026-07-24 14:18 UTCEPSS rescore
  10. 2026-07-24 14:18 UTCEPSS rescore
  11. 2026-07-23 14:18 UTCEPSS rescore
  12. 2026-07-23 14:18 UTCEPSS rescore
  13. 2026-07-23 03:21 UTCEG score recompute
  14. 2026-07-22 14:08 UTCEPSS rescore
  15. 2026-07-22 14:08 UTCEPSS rescore
  16. 2026-07-21 15:25 UTCEPSS rescore
  17. 2026-07-21 15:25 UTCEPSS rescore
  18. 2026-07-20 17:08 UTCEPSS rescore
  19. 2026-07-19 14:31 UTCEPSS rescore
  20. 2026-07-19 02:29 UTCEPSS rescore
  21. 2026-07-18 10:04 UTCEPSS rescore
  22. 2026-07-17 22:59 UTCOSV refresh
  23. 2026-07-16 17:03 UTCEPSS rescore
  24. 2026-07-15 16:57 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
Show 75 more
  1. 2026-07-15 02:00 UTCEPSS rescore
  2. 2026-07-15 01:23 UTCNVD updateCVSS v3 → 5.9 · severity → MEDIUM
  3. 2026-07-15 00:50 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  4. 2026-07-13 22:31 UTCEPSS rescore
  5. 2026-07-13 06:13 UTCEPSS rescore
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-12 05:46 UTCEPSS rescore
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-09 19:10 UTCEPSS rescore
  11. 2026-07-09 19:10 UTCEPSS rescore
  12. 2026-07-08 15:16 UTCEPSS rescore
  13. 2026-07-08 15:16 UTCEPSS rescore
  14. 2026-07-06 16:27 UTCEPSS rescore
  15. 2026-07-06 16:27 UTCEPSS rescore
  16. 2026-07-06 02:23 UTCEPSS rescore
  17. 2026-07-06 02:23 UTCEPSS rescore
  18. 2026-07-05 02:31 UTCEPSS rescore
  19. 2026-07-05 02:30 UTCEPSS rescore
  20. 2026-07-04 06:31 UTCEPSS rescore
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-01 15:07 UTCEPSS rescore
  23. 2026-06-30 23:22 UTCEPSS rescore
  24. 2026-06-30 04:33 UTCNVD updateCVSS v3 → 5.9 · severity → MEDIUM
  25. 2026-06-29 20:29 UTCVendor advisory
  26. 2026-06-29 20:29 UTCGHSA enrichment
  27. 2026-06-29 14:06 UTCEPSS rescore
  28. 2026-06-28 09:21 UTCVendor advisory
  29. 2026-06-28 09:21 UTCGHSA enrichment
  30. 2026-06-28 04:56 UTCEPSS rescore
  31. 2026-06-27 20:48 UTCVendor advisory
  32. 2026-06-27 20:48 UTCGHSA enrichment
  33. 2026-06-27 08:05 UTCVendor advisory
  34. 2026-06-27 08:05 UTCGHSA enrichment
  35. 2026-06-27 03:08 UTCEPSS rescore
  36. 2026-06-26 19:34 UTCVendor advisory
  37. 2026-06-26 19:34 UTCGHSA enrichment
  38. 2026-06-26 04:07 UTCVendor advisory
  39. 2026-06-26 04:07 UTCGHSA enrichment
  40. 2026-06-25 15:35 UTCVendor advisory
  41. 2026-06-25 15:35 UTCGHSA enrichment
  42. 2026-06-25 13:50 UTCEPSS rescore
  43. 2026-06-24 14:05 UTCEPSS rescore
  44. 2026-06-23 21:33 UTCEPSS rescore
  45. 2026-06-23 21:33 UTCEPSS rescore
  46. 2026-06-22 14:25 UTCEPSS rescore
  47. 2026-06-22 14:25 UTCEPSS rescore
  48. 2026-06-21 14:56 UTCEPSS rescore
  49. 2026-06-21 14:56 UTCEPSS rescore
  50. 2026-06-21 01:59 UTCEPSS rescore
  51. 2026-06-21 01:59 UTCEPSS rescore
  52. 2026-06-19 19:26 UTCEPSS rescore
  53. 2026-06-19 19:26 UTCEPSS rescore
  54. 2026-06-18 17:52 UTCEPSS rescore
  55. 2026-06-18 17:52 UTCEPSS rescore
  56. 2026-06-17 23:56 UTCVendor advisory
  57. 2026-06-17 23:56 UTCGHSA enrichment
  58. 2026-06-17 17:53 UTCEPSS rescore
  59. 2026-06-17 11:26 UTCVendor advisory
  60. 2026-06-17 11:26 UTCGHSA enrichment
  61. 2026-06-16 20:13 UTCVendor advisory
  62. 2026-06-16 20:13 UTCGHSA enrichment
  63. 2026-06-16 17:53 UTCEPSS rescore
  64. 2026-06-16 04:53 UTCVendor advisory
  65. 2026-06-16 04:52 UTCGHSA enrichment
  66. 2026-06-15 17:49 UTCEPSS rescore
  67. 2026-06-15 17:49 UTCEPSS rescore
  68. 2026-06-15 15:51 UTCVendor advisory
  69. 2026-06-15 15:51 UTCGHSA enrichment
  70. 2026-06-14 23:31 UTCVendor advisory
  71. 2026-06-14 23:31 UTCGHSA enrichment
  72. 2026-06-14 23:18 UTCEPSS rescore
  73. 2026-06-14 11:00 UTCVendor advisory
  74. 2026-06-14 10:59 UTCGHSA enrichment
  75. 2026-06-13 23:00 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-5947?
CVE-2026-5947 is a high vulnerability published on May 20, 2026. Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query…
When was CVE-2026-5947 disclosed?
CVE-2026-5947 was first published in the National Vulnerability Database on May 20, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-5947 actively exploited?
CVE-2026-5947 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 30.6% of all scored CVEs.
What is the CVSS score of CVE-2026-5947?
CVE-2026-5947 has a CVSS v3 base score of 5.9 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.5.
How do I remediate CVE-2026-5947?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-5947, 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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