FKIE_CVE-2026-3591

Vulnerability from fkie_nvd - Published: 2026-03-25 14:16 - Updated: 2026-03-25 15:41
Severity ?
5.4 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Summary
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.
References
security-officer@isc.orghttps://downloads.isc.org/isc/bind9/9.20.21
security-officer@isc.orghttps://downloads.isc.org/isc/bind9/9.21.20
security-officer@isc.orghttps://kb.isc.org/docs/cve-2026-3591
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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.\nThis 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.\nBIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected."
    }
  ],
  "id": "CVE-2026-3591",
  "lastModified": "2026-03-25T15:41:33.977",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.4,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 2.5,
        "source": "security-officer@isc.org",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-03-25T14:16:37.297",
  "references": [
    {
      "source": "security-officer@isc.org",
      "url": "https://downloads.isc.org/isc/bind9/9.20.21"
    },
    {
      "source": "security-officer@isc.org",
      "url": "https://downloads.isc.org/isc/bind9/9.21.20"
    },
    {
      "source": "security-officer@isc.org",
      "url": "https://kb.isc.org/docs/cve-2026-3591"
    }
  ],
  "sourceIdentifier": "security-officer@isc.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-305"
        },
        {
          "lang": "en",
          "value": "CWE-562"
        }
      ],
      "source": "security-officer@isc.org",
      "type": "Secondary"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.