CVE-2025-40777

Summary: CVE-2025-40777 affects ISC BIND 9 where a named caching resolver configured with serve-stale-enable=yes and stale-answer-client-timeout=0 can abort due to an assertion failure while resolving a CNAME chain. Affected versions include BIND 9.20.0–9.20.10, 9.21.0–9.21.9, and 9.20.9-S1–9.20....