ubuntu-cve-2026-3591
Vulnerability from osv_ubuntu
Published
2026-03-25 00:00
Modified
2026-05-20 15:24
Summary
Details

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.

Severity
5.4 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "isc-dhcp-client",
            "binary_version": "4.3.5-3ubuntu7.4"
          },
          {
            "binary_name": "isc-dhcp-client-ddns",
            "binary_version": "4.3.5-3ubuntu7.4"
          },
          {
            "binary_name": "isc-dhcp-common",
            "binary_version": "4.3.5-3ubuntu7.4"
          },
          {
            "binary_name": "isc-dhcp-relay",
            "binary_version": "4.3.5-3ubuntu7.4"
          },
          {
            "binary_name": "isc-dhcp-server",
            "binary_version": "4.3.5-3ubuntu7.4"
          },
          {
            "binary_name": "isc-dhcp-server-ldap",
            "binary_version": "4.3.5-3ubuntu7.4"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "isc-dhcp",
        "purl": "pkg:deb/ubuntu/isc-dhcp@4.3.5-3ubuntu7.4?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.3.5-3ubuntu2",
        "4.3.5-3ubuntu3",
        "4.3.5-3ubuntu4",
        "4.3.5-3ubuntu5",
        "4.3.5-3ubuntu6",
        "4.3.5-3ubuntu7",
        "4.3.5-3ubuntu7.1",
        "4.3.5-3ubuntu7.2",
        "4.3.5-3ubuntu7.3",
        "4.3.5-3ubuntu7.4"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbind9-161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libdns-export1109",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libdns1109",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libirs-export161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libirs161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisc-export1105",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisc1105",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisccc-export161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisccc161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisccfg-export163",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "libisccfg163",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          },
          {
            "binary_name": "liblwres161",
            "binary_version": "1:9.11.16+dfsg-3~ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "bind9-libs",
        "purl": "pkg:deb/ubuntu/bind9-libs@1:9.11.16+dfsg-3~ubuntu1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:9.11.16+dfsg-3~build1",
        "1:9.11.16+dfsg-3~ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libbind9-161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libdns-export1110",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libdns1110",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libirs-export161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libirs161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisc-export1105",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisc1105",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisccc-export161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisccc161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisccfg-export163",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "libisccfg163",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          },
          {
            "binary_name": "liblwres161",
            "binary_version": "1:9.11.19+dfsg-2.1ubuntu3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "bind9-libs",
        "purl": "pkg:deb/ubuntu/bind9-libs@1:9.11.19+dfsg-2.1ubuntu3?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:9.11.19+dfsg-2.1ubuntu1",
        "1:9.11.19+dfsg-2.1ubuntu2",
        "1:9.11.19+dfsg-2.1ubuntu3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "isc-dhcp-client",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-client-ddns",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-common",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-keama",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-relay",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server-ldap",
            "binary_version": "4.4.3-P1-4ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "isc-dhcp",
        "purl": "pkg:deb/ubuntu/isc-dhcp@4.4.3-P1-4ubuntu2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.4.3-P1-2ubuntu5",
        "4.4.3-P1-4ubuntu1",
        "4.4.3-P1-4ubuntu2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "bind9",
            "binary_version": "1:9.20.11-1ubuntu2.2"
          },
          {
            "binary_name": "bind9-dnsutils",
            "binary_version": "1:9.20.11-1ubuntu2.2"
          },
          {
            "binary_name": "bind9-host",
            "binary_version": "1:9.20.11-1ubuntu2.2"
          },
          {
            "binary_name": "bind9-libs",
            "binary_version": "1:9.20.11-1ubuntu2.2"
          },
          {
            "binary_name": "bind9-utils",
            "binary_version": "1:9.20.11-1ubuntu2.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "bind9",
        "purl": "pkg:deb/ubuntu/bind9@1:9.20.11-1ubuntu2.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1:9.20.11-1ubuntu2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1:9.20.4-3ubuntu1",
        "1:9.20.4-3ubuntu2",
        "1:9.20.4-3ubuntu3",
        "1:9.20.9-2ubuntu1",
        "1:9.20.10-1ubuntu1",
        "1:9.20.11-1ubuntu1",
        "1:9.20.11-1ubuntu2",
        "1:9.20.11-1ubuntu2.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "isc-dhcp-client",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-client-ddns",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-common",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-keama",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-relay",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server-ldap",
            "binary_version": "4.4.3-P1-4ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "isc-dhcp",
        "purl": "pkg:deb/ubuntu/isc-dhcp@4.4.3-P1-4ubuntu2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.4.3-P1-4ubuntu2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "isc-dhcp-client",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-client-ddns",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-common",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-keama",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-relay",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server",
            "binary_version": "4.4.3-P1-4ubuntu2"
          },
          {
            "binary_name": "isc-dhcp-server-ldap",
            "binary_version": "4.4.3-P1-4ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "isc-dhcp",
        "purl": "pkg:deb/ubuntu/isc-dhcp@4.4.3-P1-4ubuntu2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.4.3-P1-4ubuntu2"
      ]
    }
  ],
  "aliases": [],
  "details": "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.",
  "id": "UBUNTU-CVE-2026-3591",
  "modified": "2026-05-20T15:24:29Z",
  "published": "2026-03-25T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-3591"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-3591"
    },
    {
      "type": "REPORT",
      "url": "https://kb.isc.org/docs/cve-2026-3591"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8124-1"
    }
  ],
  "related": [
    "USN-8124-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-3591"
  ]
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • 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.