Microsoft Security Response Center guidance
Vendor revision: Aug 7, 2026CBL-Mariner Releases
Vendor-listed releases
- 9.20.26-1
Vulnerability intelligence
CVE-2026-11605 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CBL-Mariner Releases
Vendor-listed releases
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.
Source: NVD