Input validation error in ISC BIND - CVE-2026-77692

Vulnerability identifier: #VU150221

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-2026-77692

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper handling of cryptographically invalid SIG(0) records in named when processing crafted DNS-over-HTTPS requests. A remote attacker can send a crafted DNS-over-HTTPS request containing a cryptographically invalid SIG(0) record and prematurely close the transport connection to cause a denial of service.

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)

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

• https://kb.isc.org/docs/cve-2026-77692

• Multiple vulnerabilities in ISC BIND
• Debian update for bind9
• SUSE update for bind
• Fedora 45 update for bind9-next
• Fedora 44 update for bind9-next
• Fedora 43 update for bind9-next
• Ubuntu update for bind9