CVE-2026-81563

Name of the Vulnerable Software and Affected Versions BIND 9 versions 9.18.0 through 9.18.50 BIND 9 versions 9.20.0 through 9.20.27 BIND 9 versions 9.21.0 through 9.21.25 BIND 9 versions 9.18.11-S1 through 9.18.50-S1 BIND 9 versions 9.20.9-S1 through 9.20.27-S1

Description A resolver may fail to properly deallocate internal resources when encountering an SVCB/HTTPS AliasMode record that references 14 or more SVCB/HTTPS ServiceMode records. Repeated occurrences of this behavior lead to resource exhaustion, which eventually prevents the resolver from performing new recursive lookups.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.