{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-5946", "assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22", "state": "PUBLISHED", "assignerShortName": "isc", "dateReserved": "2026-04-09T06:40:07.319Z", "datePublished": "2026-05-20T13:10:03.479Z", "dateUpdated": "2026-05-20T13:40:20.966Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "404fd4d2-a609-4245-b543-2c944a302a22", "shortName": "isc", "dateUpdated": "2026-05-20T13:10:03.479Z"}, "title": "Invalid handling of CLASS != IN", "datePublic": "2026-05-20T00:00:00.000Z", "affected": [{"vendor": "ISC", "product": "BIND 9", "versions": [{"version": "9.11.0", "lessThanOrEqual": "9.16.50", "status": "affected", "versionType": "custom"}, {"version": "9.18.0", "lessThanOrEqual": "9.18.48", "status": "affected", "versionType": "custom"}, {"version": "9.20.0", "lessThanOrEqual": "9.20.22", "status": "affected", "versionType": "custom"}, {"version": "9.21.0", "lessThanOrEqual": "9.21.21", "status": "affected", "versionType": "custom"}, {"version": "9.11.3-S1", "lessThanOrEqual": "9.16.50-S1", "status": "affected", "versionType": "custom"}, {"version": "9.18.11-S1", "lessThanOrEqual": "9.18.48-S1", "status": "affected", "versionType": "custom"}, {"version": "9.20.9-S1", "lessThanOrEqual": "9.20.22-S1", "status": "affected", "versionType": "custom"}], "defaultStatus": "unaffected"}], "cpeApplicability": [{"nodes": [{"operator": "OR", "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.11.0", "versionEndIncluding": "9.16.50"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.18.0", "versionEndIncluding": "9.18.48"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.20.0", "versionEndIncluding": "9.20.22"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.21.0", "versionEndIncluding": "9.21.21"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.11.3-S1", "versionEndIncluding": "9.16.50-S1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.18.11-S1", "versionEndIncluding": "9.18.48-S1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.20.9-S1", "versionEndIncluding": "9.20.22-S1"}]}]}], "metrics": [{"cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "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"}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-20", "description": "CWE-20 Improper Input Validation"}, {"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}, {"lang": "en", "type": "CWE", "cweId": "CWE-617", "description": "CWE-617 Reachable Assertion"}, {"lang": "en", "type": "CWE", "cweId": "CWE-754", "description": "CWE-754 Improper Check for Unusual or Exceptional Conditions"}, {"lang": "en", "type": "CWE", "cweId": "CWE-843", "description": "CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')"}]}], "descriptions": [{"lang": "en", "value": "Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) \u2014 for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. 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