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{"bugzilla": {"description": "bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records", "id": "2535432", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2535432"}, "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-606", "details": ["A flaw was found in BIND 9. A remote attacker can exploit this vulnerability by querying a BIND resolver for the root of a specially crafted, cached tree of SVCB/HTTPS AliasMode records. This action causes the resolver to spend a disproportionate amount of CPU time constructing the response, leading to a denial of service (DoS) condition. This can make the affected BIND 9 resolver unresponsive to legitimate requests."], "mitigation": {"lang": "en:us", "value": "To mitigate the risk of this denial of service, configure BIND resolvers to restrict recursive queries to trusted clients only. This can be achieved by setting the `allow-recursion` option in the `named.conf` configuration file to specific IP addresses or networks. After modifying the configuration, the `named` service must be reloaded for the changes to take effect, which may temporarily interrupt DNS resolution."}, "name": "CVE-2026-81736", "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": "Not affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "bind", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "bind9.16", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not 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": "Not 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": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-16T13:44:28Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-81736\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-81736\nhttps://downloads.isc.org/isc/bind9/9.20.29\nhttps://downloads.isc.org/isc/bind9/9.21.26\nhttps://kb.isc.org/docs/cve-2026-81736"], "statement": "This is an Important denial of service vulnerability in BIND 9 resolvers. An attacker can remotely trigger excessive CPU consumption by querying a resolver that has cached a specific tree of SVCB/HTTPS AliasMode records. This can lead to service disruption, particularly for resolvers exposed to untrusted networks.", "threat_severity": "Important"}

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