CVE-2026-3591

MEDIUMNVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

Score 5.4 from GitHub Security Advisory published 2026-03-25. NVD baseline CVSS 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

A fix is available — apply it.

A use-after-return vulnerability exists in the named server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

CVSS v3
5.4
EG Score
5.4(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
29%
KEV
Not listed

Published

March 25, 2026

Last Modified

June 17, 2026

Advisory Details (3)

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

CVE-2026-3591: A stack use-after-return flaw in SIG(0) handling code may enable ACL bypass

https://kb.isc.org/docs/cve-2026-3591
generic

Index of /isc/bind9/9.21.20

https://downloads.isc.org/isc/bind9/9.21.20
generic

Index of /isc/bind9/9.20.21

https://downloads.isc.org/isc/bind9/9.20.21

Vendor Advisories for CVE-2026-3591(2)

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 (1:9.20.11-1ubuntu2.2) @ questing2026-06-11ubuntu
redhatbind-main-9.18.48-1.hum12026-04-07redhat

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:v3.22(1)
PackageVulnerable rangeFixed inDependents
bind—9.20.21-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
bind—9.20.21-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
bind—9.20.21-r0—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
bind91:9.20.11-4 ... 1:9.20.21-1~deb13u1~bpo12+1 (13 versions)1:9.20.21-1~deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
bind91:9.20.11-4 ... 1:9.20.21-1~deb13u1~bpo12+1 (14 versions)1:9.20.21-1—

Weakness Classification(2)

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

Frequently asked(5)

What is CVE-2026-3591?
CVE-2026-3591 is a medium vulnerability published on March 25, 2026. A use-after-return vulnerability exists in the named server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead…
When was CVE-2026-3591 disclosed?
CVE-2026-3591 was first published in the National Vulnerability Database on March 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-3591 actively exploited?
CVE-2026-3591 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 71.3% of all scored CVEs.
What is the CVSS score of CVE-2026-3591?
CVE-2026-3591 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-3591?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-3591, 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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