{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
            "extracted_events": [
              {
                "introduced": "9.18.36"
              },
              {
                "fixed": "9.18.49"
              },
              {
                "introduced": "9.20.8"
              },
              {
                "fixed": "9.20.23"
              },
              {
                "introduced": "9.21.7"
              },
              {
                "fixed": "9.21.21"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "20451734dd92248cb87778a98dc8d827b766be20"
            },
            {
              "fixed": "cd4a53b4630ba8646b2071ea8161d578b4185a94"
            },
            {
              "introduced": "6400fd6c05506b7c67b9384ac659ba3af553e4ba"
            },
            {
              "fixed": "7d0b4d4d436e7b950225a533e5bc56d8f935cc1c"
            },
            {
              "introduced": "6a06226c0fc2ef665a787290672ed8189a44d8a5"
            },
            {
              "fixed": "ec2e1ce35a5ad648088f4821c9114e739e117c1c"
            }
          ],
          "repo": "https://github.com/isc-projects/bind9",
          "type": "GIT"
        }
      ]
    },
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*",
            "extracted_events": [
              {
                "introduced": "9.18.36"
              },
              {
                "fixed": "9.18.49"
              },
              {
                "introduced": "9.20.8"
              },
              {
                "fixed": "9.20.23"
              },
              {
                "introduced": "9.21.7"
              },
              {
                "fixed": "9.21.21"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "20451734dd92248cb87778a98dc8d827b766be20"
            },
            {
              "fixed": "cd4a53b4630ba8646b2071ea8161d578b4185a94"
            },
            {
              "introduced": "6400fd6c05506b7c67b9384ac659ba3af553e4ba"
            },
            {
              "fixed": "7d0b4d4d436e7b950225a533e5bc56d8f935cc1c"
            },
            {
              "introduced": "6a06226c0fc2ef665a787290672ed8189a44d8a5"
            },
            {
              "fixed": "ec2e1ce35a5ad648088f4821c9114e739e117c1c"
            }
          ],
          "repo": "https://gitlab.isc.org/isc-projects/bind9",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {},
  "details": "An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions.\nThis issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.",
  "id": "CVE-2026-5950",
  "modified": "2026-07-08T05:38:08.346615395Z",
  "published": "2026-05-20T13:16:40.450Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://kb.isc.org/docs/cve-2026-5950"
    },
    {
      "type": "FIX",
      "url": "https://downloads.isc.org/isc/bind9/9.18.49"
    },
    {
      "type": "FIX",
      "url": "https://downloads.isc.org/isc/bind9/9.20.23"
    },
    {
      "type": "FIX",
      "url": "https://downloads.isc.org/isc/bind9/9.21.22"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ]
}