CVE-2026-19666 Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path

On a resolver configured to use dns64, if an applicable answer from the authoritative server is malformed in a specific way, the resolver named process will exit unexpectedly. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1...

CVE-2026-19666

BIND 9 named contains a use-after-free vulnerability in query_addnoqnameproof() along the DNS64 filter64 code path. When a resolver is configured with dns64 and receives a malformed answer from an authoritative server, the named process exits unexpectedly, causing a denial of service (CVSS 7.5 HI...