CVE-2026-77119
Published:September 16, 2026
Updated:September 22, 2026
A validly signed NSEC3 from an unrelated sibling zone may be accepted as an insecurity proof, downgrading a secure delegation and letting a forged unsigned answer through.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Affected Packages
https://github.com/isc-projects/bind9.git (GITHUB):
Affected version(s) >=v9.20.0 <v9.20.29Fix Suggestion:
Update to version v9.20.29https://github.com/isc-projects/bind9.git (GITHUB):
Affected version(s) >=v9.21.0 <v9.21.26Fix Suggestion:
Update to version v9.21.26Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Origin Validation Error
EPSS
Base Score:
0.19