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CVE-2026-33596

Full vulnerability record from the local CVENow database.

Description

A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed queries that are routed to a TCP-only or DNS over TLS backend.

Severity
MEDIUM
CVSS score
6.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-04-22 14:16:54.073000
Last modified
2026-10-26 21:10:00.170000
View original CVE JSON
{
  "id": "CVE-2026-33596",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-22T14:16:54.073",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A client might theoretically be able to cause a mismatch between queries sent to a backend and the received responses by sending a flood of perfectly timed queries that are routed to a TCP-only or DNS over TLS backend."
    },
    {
      "lang": "es",
      "value": "Un cliente podría teóricamente causar un desajuste entre las consultas enviadas a un backend y las respuestas recibidas enviando una avalancha de consultas perfectamente sincronizadas que se enrutan a un backend solo TCP o DNS sobre TLS."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "PowerDNS",
          "product": "DNSdist",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.powerdns.com/",
          "packageName": "dnsdist",
          "modules": [
            "Outgoing DNS over TCP"
          ],
          "programFiles": [
            "dnsdist-tcp-downstream.hh"
          ],
          "repo": "https://github.com/PowerDNS/pdns",
          "versions": [
            {
              "version": "1.9.0",
              "lessThan": "1.9.13",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "2.0.0",
              "lessThan": "2.0.4",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 3.1,
          "baseSeverity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 1.4
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-04-22T14:43:12.207234Z",
          "id": "CVE-2026-33596",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-190"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.9.0",
              "versionEndExcluding": "1.9.13",
              "matchCriteriaId": "DCC2DF11-EC5C-4112-90F2-C266CB65D390"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:powerdns:dnsdist:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "2.0.0",
              "versionEndExcluding": "2.0.4",
              "matchCriteriaId": "29865EC6-C1A0-40F3-B0BB-7F71F9C1DCB7"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-04.html",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    }
  ]
}