CVE-2026-40211

{
  "id": "CVE-2026-40211",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-25T13:16:39.717",
  "lastModified": "2026-10-25T23:10:00.167",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An attacker can send crafted DNS over HTTP/3 queries, triggering an exception that prevents some buffer from being freed right away. The buffer will be freed at the end of the QUIC connection, but on some setups it might be possible to open enough concurrent DoH3 streams to trigger an out-of-memory condition, resulting in a denial of service."
    },
    {
      "lang": "es",
      "value": "Un atacante puede enviar consultas DNS sobre HTTP/3 manipuladas, lo que desencadena una excepción que impide que algún búfer se libere de inmediato. El búfer se liberará al final de la conexión QUIC, pero en algunas configuraciones podría ser posible abrir suficientes flujos DoH3 concurrentes para desencadenar una condición de falta de memoria, lo que resulta en una denegación de servicio."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "PowerDNS",
          "product": "DNSdist",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.powerdns.com/",
          "packageName": "dnsdist",
          "modules": [
            "DNS over HTTP3"
          ],
          "programFiles": [
            "dnsdist-crypto.cc"
          ],
          "repo": "https://github.com/PowerDNS/pdns",
          "versions": [
            {
              "version": "1.9.0",
              "lessThan": "1.9.15",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "2.0.0",
              "lessThan": "2.0.7",
              "versionType": "semver",
              "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:L",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-25T13:44:56.582604Z",
          "id": "CVE-2026-40211",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html",
      "source": "[email protected]"
    }
  ]
}