A bug during bad server handling could cause the resolver to enter an infinite loop, continuously sending queries to an upstream server with no exit condition, until the resolver query timeout was hit. This has been fixed.
ISC would like to thank Billy Baraja (BielraX) for bringing this issue to our attention.
Closesisc-projects/bind9#5804
Resolves: RHEL-189756
CVE: CVE-2026-5950