CVE-2026-12617 (GCVE-0-2026-12617)

Vulnerability from cvelistv5 – Published: 2026-07-22 14:14 – Updated: 2026-07-22 14:14
VLAI
Title
Record ordering based unexpected exit with CNAME or DNAME
Summary
The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
Assigner
isc
References
Impacted products
Vendor Product Version
ISC BIND 9 Affected: 9.18.0 , ≤ 9.18.50 (custom)
Affected: 9.20.0 , ≤ 9.20.24 (custom)
Affected: 9.18.11-S1 , ≤ 9.18.50-S1 (custom)
Affected: 9.20.9-S1 , ≤ 9.20.24-S1 (custom)
Create a notification for this product.
Date Public
2026-07-22 00:00
Credits
ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention.
Show details on NVD website
To clipboard 

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          "product": "BIND 9",
          "vendor": "ISC",
          "versions": [
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              "status": "affected",
              "version": "9.18.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.20.24",
              "status": "affected",
              "version": "9.20.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.18.50-S1",
              "status": "affected",
              "version": "9.18.11-S1",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.20.24-S1",
              "status": "affected",
              "version": "9.20.9-S1",
              "versionType": "custom"
            }
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        }
      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
                {
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                  "versionEndIncluding": "9.18.50",
                  "versionStartIncluding": "9.18.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.20.24",
                  "versionStartIncluding": "9.20.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.18.50-S1",
                  "versionStartIncluding": "9.18.11-S1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.20.24-S1",
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                }
              ],
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
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          "value": "ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention."
        }
      ],
      "datePublic": "2026-07-22T00:00:00.000Z",
      "descriptions": [
        {
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        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "We are not aware of any active exploits."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "If one of these situations is encountered, BIND may exit with an assertion."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-617",
              "description": "CWE-617 Reachable Assertion",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-22T14:14:46.397Z",
        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "shortName": "isc"
      },
      "references": [
        {
          "name": "CVE-2026-12617",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://kb.isc.org/docs/cve-2026-12617"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://downloads.isc.org/isc/bind9/9.20.26"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.26 or 9.20.26-S1."
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Record ordering based unexpected exit with CNAME or DNAME",
      "workarounds": [
        {
          "lang": "en",
          "value": "No workarounds known."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22",
    "assignerShortName": "isc",
    "cveId": "CVE-2026-12617",
    "datePublished": "2026-07-22T14:14:46.397Z",
    "dateReserved": "2026-06-18T13:52:43.335Z",
    "dateUpdated": "2026-07-22T14:14:46.397Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-12617\",\"sourceIdentifier\":\"security-officer@isc.org\",\"published\":\"2026-07-22T15:16:51.963\",\"lastModified\":\"2026-07-22T15:16:51.963\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur.\\nThis issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.\"}],\"affected\":[{\"source\":\"security-officer@isc.org\",\"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\":\"9.20.24\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.18.11-S1\",\"lessThanOrEqual\":\"9.18.50-S1\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.20.9-S1\",\"lessThanOrEqual\":\"9.20.24-S1\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-officer@isc.org\",\"type\":\"Primary\",\"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}]},\"weaknesses\":[{\"source\":\"security-officer@isc.org\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-617\"}]}],\"references\":[{\"url\":\"https://downloads.isc.org/isc/bind9/9.20.26\",\"source\":\"security-officer@isc.org\"},{\"url\":\"https://kb.isc.org/docs/cve-2026-12617\",\"source\":\"security-officer@isc.org\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-07-22T15:46:09+00:00",
      "cve": "CVE-2026-12617",
      "id": "CVE-2026-12617",
      "initial_release_date": "2026-07-22T00:00:00+00:00",
      "product_status:known_affected": "87",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "bind: bind9: Record ordering based unexpected exit with CNAME or DNAME",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12617.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.