Use-after-free in ISC BIND - CVE-2026-3593
Published: May 22, 2026
Vulnerability identifier: #VU132117
CSH Severity: Medium
CVSS v4: 8.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-3593
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information and cause a denial of service.
The vulnerability exists due to use-after-free in the DNS-over-HTTPS implementation when processing crafted HTTP/2 traffic sent to a DNS-over-HTTPS endpoint. A remote attacker can send crafted HTTP/2 traffic to disclose sensitive information and cause a denial of service.
Both authoritative servers and resolvers are affected.
Affected software
ISC BIND
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
openSUSE Leap
Ubuntu
Fedora
LANTIME Operating System Firmware (LTOS)
bind9 (Ubuntu package)
bind9 (Debian package)
bind
bind-utils
bind-debuginfo
bind-utils-debuginfo
bind-debugsource
bind-doc
bind9-next
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
openSUSE Leap
Ubuntu
Fedora
LANTIME Operating System Firmware (LTOS)
bind9 (Ubuntu package)
bind9 (Debian package)
bind
bind-utils
bind-debuginfo
bind-utils-debuginfo
bind-debugsource
bind-doc
bind9-next
How to mitigate CVE-2026-3593
Install security update from vendor's website.
ISC BIND - addressed in versions 9.20.23, 9.20.23-S1, 9.21.22
LANTIME Operating System Firmware (LTOS) - update to 7.10.012
bind9 (Ubuntu package) - addressed in versions 1:9.18.39-0ubuntu0.22.04.4, 1:9.18.39-0ubuntu0.24.04.5, 1:9.20.11-1ubuntu2.4, 1:9.20.18-1ubuntu2.1
bind9 (Debian package) - addressed in versions 1:9.18.49-1~deb12u1, 1:9.20.23-1~deb13u1
bind - update to 9.18.49-150600.3.26.1
bind-utils - update to 9.18.49-150600.3.26.1
bind-debuginfo - update to 9.18.49-150600.3.26.1
bind-utils-debuginfo - update to 9.18.49-150600.3.26.1
bind-debugsource - update to 9.18.49-150600.3.26.1
bind-doc - update to 9.18.49-150600.3.26.1
bind9-next - addressed in versions 9.21.22-2.fc43, 9.21.22-2.fc44
LANTIME Operating System Firmware (LTOS) - update to 7.10.012
bind9 (Ubuntu package) - addressed in versions 1:9.18.39-0ubuntu0.22.04.4, 1:9.18.39-0ubuntu0.24.04.5, 1:9.20.11-1ubuntu2.4, 1:9.20.18-1ubuntu2.1
bind9 (Debian package) - addressed in versions 1:9.18.49-1~deb12u1, 1:9.20.23-1~deb13u1
bind - update to 9.18.49-150600.3.26.1
bind-utils - update to 9.18.49-150600.3.26.1
bind-debuginfo - update to 9.18.49-150600.3.26.1
bind-utils-debuginfo - update to 9.18.49-150600.3.26.1
bind-debugsource - update to 9.18.49-150600.3.26.1
bind-doc - update to 9.18.49-150600.3.26.1
bind9-next - addressed in versions 9.21.22-2.fc43, 9.21.22-2.fc44