{"id":"CVE-2026-81563","title":"A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources","summary":"A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-401","CWE-772"],"vendor":"ISC","product":"BIND 9","affected":["bind_9 >= 9.18.0 <= 9.18.50","bind_9 >= 9.20.0 <= 9.20.27","bind_9 >= 9.21.0 <= 9.21.25","bind_9 >= 9.18.11-S1 <= 9.18.50-S1","bind_9 >= 9.20.9-S1 <= 9.20.27-S1"],"published":"2026-09-16","updated":"2026-09-17","sourceUpdated":"2026-09-17T18:17:09.147","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81563","references":[{"url":"https://downloads.isc.org/isc/bind9/9.20.29","label":"security-officer@isc.org"},{"url":"https://downloads.isc.org/isc/bind9/9.21.26","label":"security-officer@isc.org"},{"url":"https://kb.isc.org/docs/cve-2026-81563","label":"security-officer@isc.org"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-81563.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-81563"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2535461"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-81563"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-81563"},{"url":"https://access.redhat.com/errata/RHSA-2026:68279"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-17T17:47:13.244761Z"},"ingestedAt":"2026-09-16T14:57:28.017Z","epss":0.0048,"epssPercentile":0.40432,"patched":["hardened_images"],"slug":"CVE-2026-81563","body":"## Overview\n\nA BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups.\nThis issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-81563.json)\n- **RHSA-2026:68279** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68279)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}