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CVE-2026-11622

Full vulnerability record from the local CVENow database.

Description

A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Undergoing Analysis
Source identifier
Published
2026-07-22 15:16:51.703000
Last modified
2026-10-24 18:10:00.163000
View original CVE JSON
{
  "id": "CVE-2026-11622",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-22T15:16:51.703",
  "lastModified": "2026-10-24T18:10:00.163",
  "vulnStatus": "Undergoing Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1."
    },
    {
      "lang": "es",
      "value": "Un resolvedor validador de DNSSEC que está bajo un ataque de subdominio aleatorio contra una zona firmada con DNSSEC puede sufrir un uso descontrolado de la memoria. El atacante necesita poder enviar consultas más rápido de lo que el resolvedor puede realizar la validación. El aumento del uso de memoria puede ser órdenes de magnitud más allá del límite configurado en el parámetro “max-cache-size”.\nEste problema afecta a las versiones de BIND 9 9.11.0 a 9.18.50, 9.20.0 a 9.20.24, 9.21.0 a 9.21.23, 9.11.3-S1 a 9.18.50-S1, y 9.20.9-S1 a 9.20.24-S1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "ISC",
          "product": "BIND 9",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "9.11.0",
              "lessThanOrEqual": "9.18.50",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.20.0",
              "lessThanOrEqual": "9.20.24",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.21.0",
              "lessThanOrEqual": "9.21.23",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.11.3-S1",
              "lessThanOrEqual": "9.18.50-S1",
              "versionType": "custom",
              "status": "affected"
            },
            {
              "version": "9.20.9-S1",
              "lessThanOrEqual": "9.20.24-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": "2026-07-22T18:53:04.346058Z",
          "id": "CVE-2026-11622",
          "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-770"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://downloads.isc.org/isc/bind9/9.20.26",
      "source": "[email protected]"
    },
    {
      "url": "https://downloads.isc.org/isc/bind9/9.21.24",
      "source": "[email protected]"
    },
    {
      "url": "https://kb.isc.org/docs/cve-2026-11622",
      "source": "[email protected]"
    }
  ]
}