Reachable assertion in ISC BIND - CVE-2026-76163
Published: September 16, 2026
Vulnerability identifier: #VU150222
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-76163
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a reachable assertion in BIND named TKEY query handling when processing a TKEY query. A remote attacker can send a TKEY query to cause a denial of service.
The issue occurs when the named.conf configuration file contains no global options block.
Affected software
ISC BIND
Debian Linux
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
Ubuntu
Basesystem Module
Server Applications Module
Fedora
bind9 (Ubuntu package)
bind-utils
bind-debuginfo
bind-utils-debuginfo
bind-debugsource
bind
bind-doc
bind9-next
bind9 (Debian package)
Debian Linux
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
Ubuntu
Basesystem Module
Server Applications Module
Fedora
bind9 (Ubuntu package)
bind-utils
bind-debuginfo
bind-utils-debuginfo
bind-debugsource
bind
bind-doc
bind9-next
bind9 (Debian package)
How to mitigate CVE-2026-76163
Install security update from vendor's website.
ISC BIND - addressed in versions 9.20.29, 9.20.29-s1, 9.21.26
bind9 (Ubuntu package) - addressed in versions 1:9.9.5.dfsg-3ubuntu0.19+esm15, 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11, 1:9.11.3+dfsg-1ubuntu1.19+esm6, 1:9.18.30-0ubuntu0.20.04.2+esm3, 1:9.18.39-0ubuntu0.22.04.7, 1:9.18.39-0ubuntu0.24.04.8, 1:9.20.24-1ubuntu0.4
bind-utils - update to 9.20.29-150700.3.32.2
bind-debuginfo - update to 9.20.29-150700.3.32.2
bind-utils-debuginfo - update to 9.20.29-150700.3.32.2
bind-debugsource - update to 9.20.29-150700.3.32.2
bind - update to 9.20.29-150700.3.32.2
bind-doc - update to 9.20.29-150700.3.32.2
bind9-next - addressed in versions 9.21.26-1.fc43, 9.21.26-1.fc44, 9.21.26-1.fc45
bind9 (Debian package) - update to 1:9.20.29-1~deb13u1
bind9 (Ubuntu package) - addressed in versions 1:9.9.5.dfsg-3ubuntu0.19+esm15, 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11, 1:9.11.3+dfsg-1ubuntu1.19+esm6, 1:9.18.30-0ubuntu0.20.04.2+esm3, 1:9.18.39-0ubuntu0.22.04.7, 1:9.18.39-0ubuntu0.24.04.8, 1:9.20.24-1ubuntu0.4
bind-utils - update to 9.20.29-150700.3.32.2
bind-debuginfo - update to 9.20.29-150700.3.32.2
bind-utils-debuginfo - update to 9.20.29-150700.3.32.2
bind-debugsource - update to 9.20.29-150700.3.32.2
bind - update to 9.20.29-150700.3.32.2
bind-doc - update to 9.20.29-150700.3.32.2
bind9-next - addressed in versions 9.21.26-1.fc43, 9.21.26-1.fc44, 9.21.26-1.fc45
bind9 (Debian package) - update to 1:9.20.29-1~deb13u1