CVE-2026-11605
Published:July 22, 2026
Updated:August 06, 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.
Affected Packages
https://github.com/isc-projects/bind9.git (GITHUB):
Affected version(s) >=v9.20.0 <v9.20.26Fix Suggestion:
Update to version v9.20.26https://github.com/isc-projects/bind9.git (GITHUB):
Affected version(s) >=v9.21.0 <v9.21.24Fix Suggestion:
Update to version v9.21.24Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Incorrect Behavior Order: Early Amplification
EPSS
Base Score:
0.52