CVE-2026-5947

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "BIND 9", "vendor": "ISC", "versions": [{"lessThanOrEqual": "9.20.22", "status": "affected", "version": "9.20.0", "versionType": "custom"}, {"lessThanOrEqual": "9.21.21", "status": "affected", "version": "9.21.0", "versionType": "custom"}, {"lessThanOrEqual": "9.20.22-S1", "status": "affected", "version": "9.20.9-S1", "versionType": "custom"}, {"lessThanOrEqual": "9.18.49", "status": "unaffected", "version": "9.18.28", "versionType": "custom"}, {"lessThanOrEqual": "9.18.49-S1", "status": "unaffected", "version": "9.18.28-S1", "versionType": "custom"}]}], "source": "security-officer@isc.org"}, {"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:hummingbird:1"], "defaultStatus": "affected", "packageName": "bind-main", "product": "Red Hat Hardened Images", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "9.18.48-1.1.hum1", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:10"], "defaultStatus": "unaffected", "packageName": "bind", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:6"], "defaultStatus": "unaffected", "packageName": "bind", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unaffected", "packageName": "bind", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:8"], "defaultStatus": "unaffected", "packageName": "bind", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:8"], "defaultStatus": "unaffected", "packageName": "bind9.16", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "unaffected", "packageName": "bind", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "unaffected", "packageName": "bind9.18", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "unaffected", "packageName": "dhcp", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:openshift:4"], "defaultStatus": "unaffected", "packageName": "openshift/ose-rhel-coreos-9", "product": "Red Hat OpenShift Container Platform 4", "vendor": "Red Hat"}], "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*", "matchCriteriaId": "D92461F1-BA01-479E-B740-38855CC216E6", "versionEndExcluding": "9.20.23", "versionStartIncluding": "9.20.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*", "matchCriteriaId": "B254E8E7-3F57-4552-ACBF-623FA481B697", "versionEndExcluding": "9.21.22", "versionStartIncluding": "9.21.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the \"recursive-clients\" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message.\nThis issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1.\nBIND 9 versions 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected."}, {"lang": "es", "value": "El comportamiento indefinido puede resultar debido a una condici\u00f3n de carrera que lleva a una violaci\u00f3n de uso despu\u00e9s de liberaci\u00f3n. Si BIND recibe un mensaje DNS entrante firmado con SIG(0), comienza a trabajar para validar esa firma. Si, durante esa validaci\u00f3n, se alcanza el l\u00edmite de 'recursive-clients' (como ocurrir\u00eda durante una inundaci\u00f3n de consultas), y ese mismo mensaje DNS es descartado seg\u00fan el l\u00edmite, hay una breve ventana de tiempo mientras la validaci\u00f3n de SIG(0) puede intentar leer el mensaje DNS ahora descartado.\nEste problema afecta a las versiones de BIND 9 9.20.0 a 9.20.22, 9.21.0 a 9.21.21, y 9.20.9-S1 a 9.20.22-S1.\nLas versiones de BIND 9 9.18.28 a 9.18.49 y 9.18.28-S1 a 9.18.49-S1 NO est\u00e1n afectadas."}], "id": "CVE-2026-5947", "lastModified": "2026-08-24T13:19:13.360", "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": "Secondary"}, {"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}, {"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": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-5947", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-20T13:39:15.454199Z", "version": "2.0.3"}}]}, "published": "2026-05-20T13:16:40.303", "references": [{"source": "security-officer@isc.org", "tags": ["Patch"], "url": "https://downloads.isc.org/isc/bind9/9.20.23"}, {"source": "security-officer@isc.org", "tags": ["Patch"], "url": "https://downloads.isc.org/isc/bind9/9.21.22"}, {"source": "security-officer@isc.org", "tags": ["Vendor Advisory"], "url": "https://kb.isc.org/docs/cve-2026-5947"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:7412"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/security/cve/CVE-2026-5947"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2479772"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-5947.json"}], "sourceIdentifier": "security-officer@isc.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-362"}, {"lang": "en", "value": "CWE-416"}], "source": "security-officer@isc.org", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-367"}], "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "type": "Secondary"}]}

{"bugzilla": {"description": "bind: SIG(0) validation during query flood may lead to undefined behavior", "id": "2479772", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2479772"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-367", "details": ["A flaw was found in BIND. A remote attacker could exploit a race condition during SIG(0) signature validation of an incoming DNS message. If the \"recursive-clients\" limit is reached and the message is discarded, a use-after-free vulnerability may occur. This could lead to undefined behavior and potentially result in a denial of service."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability."}, "name": "CVE-2026-5947", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "bind9.16", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "bind9.18", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "dhcp", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "bind", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-05-21T12:15:50Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-5947\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-5947"], "statement": "Important: A race condition in BIND's SIG(0) validation process can lead to undefined behavior and a denial of service when the server is under a query flood and processing signed DNS messages. This flaw could disrupt critical DNS resolution services in Red Hat environments.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[9.20.0,9.20.22]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[9.21.0,9.21.21]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[9.20.9-S1,9.20.22-S1]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[9.18.28,9.18.49]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[9.18.28-S1,9.18.49-S1]"}}], "enrichment": {"confidence": 90.0, "confidence_source": "inferred", "scores": [{"score": 90.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "BIND 9", "source": "cna", "vendor": "ISC"}, "product": "bind", "vendor": "isc"}], "created": "2026-05-20T14:45:32.835441+00:00", "updated": "2026-06-18T08:00:16.445255+00:00", "vendors": ["isc", "isc$PRODUCT$bind"]}