CVE-2026-81736

{
  "id": "CVE-2026-81736",
  "sourceIdentifier": "[email protected]",
  "published": "2026-09-16T14:17:10.817",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.\nThis issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1."
    },
    {
      "lang": "es",
      "value": "Si un resolvedor BIND tiene en caché un árbol de registros SVCB/HTTPS AliasMode y luego se le consulta por la raíz de ese árbol, el resolvedor gastará un tiempo de CPU desproporcionado construyendo la respuesta.  \\nEste problema afecta a BIND?9 desde la versión?9.18.0 hasta la versión?9.18.50 incluida, desde la versión?9.20.0 hasta la versión?9.20.27 incluida, desde la versión?9.21.0 hasta la versión?9.21.25 incluida, desde la versión?9.18.11?S1 hasta la versión?9.18.50?S1 incluida, y desde la versión?9.20.9?S1 hasta la versión?9.20.27?S1 incluida."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "ISC",
          "product": "BIND 9",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "9.18.0",
              "lessThanOrEqual": "9.18.50",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.20.0",
              "lessThanOrEqual": "9.20.27",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.21.0",
              "lessThanOrEqual": "9.21.25",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.18.11-S1",
              "lessThanOrEqual": "9.18.50-S1",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.20.9-S1",
              "lessThanOrEqual": "9.20.27-S1",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-09-17T18:45:52.174550Z",
          "id": "CVE-2026-81736",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-1050"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://downloads.isc.org/isc/bind9/9.20.29",
      "source": "[email protected]"
    },
    {
      "url": "https://downloads.isc.org/isc/bind9/9.21.26",
      "source": "[email protected]"
    },
    {
      "url": "https://kb.isc.org/docs/cve-2026-81736",
      "source": "[email protected]"
    }
  ]
}