The issue is a resource exhaustion vulnerability...
High severity
Unreviewed
Published
Jul 22, 2026
to the GitHub Advisory Database
•
Updated Jul 22, 2026
Description
Published by the National Vulnerability Database
Jul 22, 2026
Published to the GitHub Advisory Database
Jul 22, 2026
Last updated
Jul 22, 2026
The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time.
This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.
References