CVE-2019-6476

Status: ModifiedHigh (7.5)—

A defect in code added to support QNAME minimization can cause named to exit with an assertion failure if a forwarder returns a referral rather than resolving the query. This affects BIND versions 9.14.0 up to 9.14.6, and 9.15.0 up to 9.15.4.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base score: 7.5

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 2.91%
Percentile among all scored CVEs: 87
Score date: 10/7/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

ISC — Bind

CWEs

CWE-617

References

Raw JSON (NVD)

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{
  "id": "CVE-2019-6476",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-officer@isc.org",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.9,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.2
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-officer@isc.org",
      "affectedData": [
        {
          "vendor": "ISC",
          "product": "BIND 9",
          "versions": [
            {
              "status": "affected",
              "version": "9.14.0 up to 9.14.6"
            },
            {
              "status": "affected",
              "version": "9.15.0 up to 9.15.4"
            }
          ]
        }
      ]
    }
  ],
  "published": "2019-10-17T20:15:12.880",
  "references": [
    {
      "url": "https://kb.isc.org/docs/cve-2019-6476",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "security-officer@isc.org"
    },
    {
      "url": "https://security.netapp.com/advisory/ntap-20191024-0004/",
      "source": "security-officer@isc.org"
    },
    {
      "url": "https://support.f5.com/csp/article/K42238532?utm_source=f5support&amp%3Butm_medium=RSS",
      "source": "security-officer@isc.org"
    },
    {
      "url": "https://kb.isc.org/docs/cve-2019-6476",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://security.netapp.com/advisory/ntap-20191024-0004/",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://support.f5.com/csp/article/K42238532?utm_source=f5support&amp%3Butm_medium=RSS",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-617"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A defect in code added to support QNAME minimization can cause named to exit with an assertion failure if a forwarder returns a referral rather than resolving the query. This affects BIND versions 9.14.0 up to 9.14.6, and 9.15.0 up to 9.15.4."
    },
    {
      "lang": "es",
      "value": "Un defecto en el código agregado para soportar la minimización de QNAME puede causar que un nombrado salga con un error de aserción si un reenviador devuelve una referencia en lugar de resolver la consulta. Esto afecta a BIND versiones 9.14.0 hasta 9.14.6 y 9.15.0 hasta 9.15.4."
    }
  ],
  "lastModified": "2026-06-17T02:39:06.833",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "139ED9D5-ED04-479F-B9E2-2E5BB257C5CB",
              "versionEndIncluding": "9.14.6",
              "versionStartIncluding": "9.14.0"
            },
            {
              "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F910D6A0-1E35-443D-A57F-C4A8951B69F3",
              "versionEndIncluding": "9.15.4",
              "versionStartIncluding": "9.15.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-officer@isc.org"
}