{"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. Specially crafted requests reaching the affected code paths \u2014 recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data \u2014 can cause assertion failures in `named`.\nThis issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1."}], "impacts": [{"descriptions": [{"lang": "en", "value": "An attacker able to send specially crafted DNS messages to an affected `named` instance can cause it to terminate unexpectedly, resulting in a denial of service."}]}], "workarounds": [{"lang": "en", "value": "Don't configure zones other than Internet (`IN`) class. Furthermore, do not expose the server that allows DNS Dynamic Update to the general Internet."}], "exploits": [{"lang": "en", "value": "We are not aware of any active exploits."}], "solutions": [{"lang": "en", "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.49, 9.20.23, 9.21.22, 9.18.49-S1, or 9.20.23-S1."}], "credits": [{"lang": "en", "value": "ISC would like to thank Mcsky23 for bringing this vulnerability to our attention."}], "references": [{"url": "https://kb.isc.org/docs/cve-2026-5946", "name": "CVE-2026-5946", "tags": ["vendor-advisory"]}, {"url": "https://downloads.isc.org/isc/bind9/9.18.49", "tags": ["patch"]}, {"url": "https://downloads.isc.org/isc/bind9/9.20.23", "tags": ["patch"]}, {"url": "https://downloads.isc.org/isc/bind9/9.21.22", "tags": ["patch"]}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-05-20T13:40:04.619504Z", "id": "CVE-2026-5946", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-20T13:40:20.966Z"}}]}}

{}

{"cveTags": [], "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. Specially crafted requests reaching the affected code paths \u2014 recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data \u2014 can cause assertion failures in `named`.\nThis issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1."}], "id": "CVE-2026-5946", "lastModified": "2026-05-20T14:04:57.320", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-officer@isc.org", "type": "Primary"}]}, "published": "2026-05-20T13:16:40.157", "references": [{"source": "security-officer@isc.org", "url": "https://downloads.isc.org/isc/bind9/9.18.49"}, {"source": "security-officer@isc.org", "url": "https://downloads.isc.org/isc/bind9/9.20.23"}, {"source": "security-officer@isc.org", "url": "https://downloads.isc.org/isc/bind9/9.21.22"}, {"source": "security-officer@isc.org", "url": "https://kb.isc.org/docs/cve-2026-5946"}], "sourceIdentifier": "security-officer@isc.org", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-617"}, {"lang": "en", "value": "CWE-754"}, {"lang": "en", "value": "CWE-843"}], "source": "security-officer@isc.org", "type": "Secondary"}]}

{}

{}