CVE-2026-11605

HIGH7.5

Unnecessary validation of DNSSEC signed records

Published Jul 22, 2026

Modified 1 months ago

Details

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

FIX

https://downloads.isc.org/isc/bind9/9.20.26

FIX

https://downloads.isc.org/isc/bind9/9.21.24

ADVISORY

https://kb.isc.org/docs/cve-2026-11605

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-11605

CVSS Analysis

CVSS v3.1

7.5