Reachable assertion in ISC BIND - CVE-2026-13204

Vulnerability identifier: #VU139207

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-2026-13204

CWE-ID: CWE-617

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 an assertion failure in the DNSSEC validation logic when validating a provably insecure domain covered by both an NSEC and NSEC3 record at the parent with an RRSIG for only one of these types. A remote attacker can provide crafted DNS data to cause a denial of service.

ISC BIND
Debian Linux
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro
SUSE Multi-Linux Manager Client Tools for SLE Micro
SUSE Manager Client Tools for SLE Micro
Anolis OS
Red Hat CodeReady Linux Builder for IBM z Systems
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux Server - AUS
Basesystem Module
Server Applications Module
openSUSE Leap
openEuler
Ubuntu
Fedora
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
bind (Red Hat package) main
bind-pkcs11-devel
bind-pkcs11
bind-libs-lite
bind-libs
bind-export-libs
bind-export-devel
bind-devel
bind-debugsource
bind-debuginfo
bind-chroot
bind
bind-utils
python3-bind
libisccc161-debuginfo
liblwres161
libisccfg163
libisccfg163-debuginfo
libisc1107
libbind9-161-debuginfo
bind-chrootenv
libbind9-161
libirs161-debuginfo
libirs161
liblwres161-debuginfo
libdns1110-debuginfo
bind-utils-debuginfo
python-bind
libdns1110
libisc1107-debuginfo-32bit
libisc1107-32bit
bind-doc
libisc1107-debuginfo
libisccc161
bind-pkcs11-libs
bind-pkcs11-utils
bind-sdb
bind-sdb-chroot
bind-license
bind-lite-devel
libirs1601-debuginfo
libisc1606
libisccfg1600-64bit
libirs1601-64bit
libisccc1600-64bit
libbind9-1600-64bit
libdns1605-64bit
libisc1606-64bit
libdns1605-debuginfo
libisccc1600-debuginfo
libbind9-1600-debuginfo
libisc1606-debuginfo
libisccc1600
libisccfg1600
libirs1601
libns1604
libns1604-debuginfo
libbind9-1600
libdns1605
libisccfg1600-debuginfo
libirs-devel
bind9.16-dnssec-utils
bind9.16
bind9.16-chroot
bind9.16-devel
bind9.16-libs
bind9.16-utils
bind9.16-doc
bind9.16-license
python3-bind9.16
bind9.16 (Red Hat package)
bind-dnssec-utils
bind-dnssec-doc
bind9 (Ubuntu package)
bind9 (Debian package)
BIG-IP DNS
Red Hat OpenShift Container Platform

Install security update from vendor's website.

ISC BIND - addressed in versions 9.20.26, 9.20.26-s1, 9.21.24
Red Hat OpenShift Container Platform - update to 4.22.11
bind (Red Hat package) main - addressed in versions 9.11.4-26.P2.el7_9.21, 9.11.36-16.el8_10.14, 9.16.23-18.el9_4.12, 9.16.23-40.el9_8.8
bind-pkcs11-devel - addressed in versions 9.11.21-25, 9.16.23-31
bind-pkcs11 - addressed in versions 9.11.21-25, 9.16.23-31
bind-libs-lite - update to 9.11.21-25
bind-libs - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-export-libs - update to 9.11.21-25
bind-export-devel - update to 9.11.21-25
bind-devel - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-debugsource - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-debuginfo - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-chroot - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-utils - addressed in versions 9.11.21-25, 9.16.23-31, 9.18.21-11, 9.20.21-4
python3-bind - addressed in versions 9.11.21-25, 9.16.23-31
libisccc161-debuginfo - update to 9.11.22-3.74.1
liblwres161 - update to 9.11.22-3.74.1
libisccfg163 - update to 9.11.22-3.74.1
bind-debuginfo - addressed in versions 9.11.22-3.74.1, 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
libisccfg163-debuginfo - update to 9.11.22-3.74.1
libisc1107 - update to 9.11.22-3.74.1
libbind9-161-debuginfo - update to 9.11.22-3.74.1
bind - addressed in versions 9.11.22-3.74.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
bind-chrootenv - addressed in versions 9.11.22-3.74.1, 9.16.6-150300.22.62.1
libbind9-161 - update to 9.11.22-3.74.1
libirs161-debuginfo - update to 9.11.22-3.74.1
libirs161 - update to 9.11.22-3.74.1
liblwres161-debuginfo - update to 9.11.22-3.74.1
libdns1110-debuginfo - update to 9.11.22-3.74.1
bind-debugsource - addressed in versions 9.11.22-3.74.1, 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
bind-utils-debuginfo - addressed in versions 9.11.22-3.74.1, 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
python-bind - update to 9.11.22-3.74.1
libdns1110 - update to 9.11.22-3.74.1
libisc1107-debuginfo-32bit - update to 9.11.22-3.74.1
libisc1107-32bit - update to 9.11.22-3.74.1
bind-doc - addressed in versions 9.11.22-3.74.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
bind-devel - addressed in versions 9.11.22-3.74.1, 9.16.6-150300.22.62.1
libisc1107-debuginfo - update to 9.11.22-3.74.1
libisccc161 - update to 9.11.22-3.74.1
bind-utils - addressed in versions 9.11.22-3.74.1, 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1, 9.18.50-150600.3.32.1, 9.20.26-150700.3.29.1
bind-chroot - addressed in versions 9.11.36-16.0.1, 9.20.26-1
bind-pkcs11-libs - update to 9.11.36-16.0.1
bind-pkcs11-utils - update to 9.11.36-16.0.1
bind-sdb - update to 9.11.36-16.0.1
bind-sdb-chroot - update to 9.11.36-16.0.1
bind-utils - addressed in versions 9.11.36-16.0.1, 9.20.26-1
bind-license - addressed in versions 9.11.36-16.0.1, 9.20.26-1
python3-bind - update to 9.11.36-16.0.1
bind-pkcs11 - update to 9.11.36-16.0.1
bind-lite-devel - update to 9.11.36-16.0.1
bind - addressed in versions 9.11.36-16.0.1, 9.20.26-1
bind-libs-lite - update to 9.11.36-16.0.1
bind-libs - addressed in versions 9.11.36-16.0.1, 9.20.26-1
bind-export-libs - update to 9.11.36-16.0.1
bind-export-devel - update to 9.11.36-16.0.1
bind-devel - addressed in versions 9.11.36-16.0.1, 9.20.26-1
bind-pkcs11-devel - update to 9.11.36-16.0.1
libirs1601-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisc1606 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
python3-bind - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1, 9.16.50-150400.5.65.1, 9.16.50-150500.8.41.1
libisccfg1600-64bit - update to 9.16.6-150000.12.91.1
libirs1601-64bit - update to 9.16.6-150000.12.91.1
libisccc1600-64bit - update to 9.16.6-150000.12.91.1
libbind9-1600-64bit - update to 9.16.6-150000.12.91.1
libdns1605-64bit - update to 9.16.6-150000.12.91.1
libisc1606-64bit - update to 9.16.6-150000.12.91.1
libdns1605-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisccc1600-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libbind9-1600-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisc1606-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisccc1600 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisccfg1600 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libirs1601 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libns1604 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libns1604-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libbind9-1600 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libdns1605 - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libisccfg1600-debuginfo - addressed in versions 9.16.6-150000.12.91.1, 9.16.6-150300.22.62.1
libirs-devel - update to 9.16.6-150300.22.62.1
bind9.16-dnssec-utils - update to 9.16.23-0.22
bind9.16 - update to 9.16.23-0.22
bind9.16-chroot - update to 9.16.23-0.22
bind9.16-devel - update to 9.16.23-0.22
bind9.16-libs - update to 9.16.23-0.22
bind9.16-utils - update to 9.16.23-0.22
bind9.16-doc - update to 9.16.23-0.22
bind9.16-license - update to 9.16.23-0.22
python3-bind9.16 - update to 9.16.23-0.22
bind9.16 (Red Hat package) - update to 9.16.23-0.22.el8_10.12
bind-dnssec-utils - addressed in versions 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-license - addressed in versions 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-dnssec-doc - addressed in versions 9.16.23-31, 9.18.21-11, 9.20.21-4
bind-pkcs11-utils - update to 9.16.23-31
bind-pkcs11-libs - update to 9.16.23-31
bind9 (Ubuntu package) - addressed in versions 1:9.18.39-0ubuntu0.22.04.6, 1:9.18.39-0ubuntu0.24.04.7, 1:9.20.24-1ubuntu0.3
bind - addressed in versions 9.18.50-2.fc43, 9.18.50-2.fc44, 9.18.50-34.fc45
bind-doc - update to 9.20.26-1
bind-dnssec-utils - update to 9.20.26-1
bind-dnssec-doc - update to 9.20.26-1
bind9 (Debian package) - update to 1:9.20.26-1~deb13u1

• https://kb.isc.org/docs/cve-2026-13204-unexpected-exit-certain-situations-nsec-nsec3
• https://kb.isc.org/docs/cve-2026-13204

• Multiple vulnerabilities in ISC BIND
• Debian update for bind9
• SUSE update for bind
• SUSE update for bind
• SUSE update for bind
• SUSE update for bind
• SUSE update for bind
• SUSE update for bind
• openEuler 24.03 LTS SP1 update for bind
• openEuler 24.03 LTS SP4 update for bind
• openEuler 24.03 LTS SP3 update for bind
• SUSE update for bind
• Anolis OS update for bind
• Red Hat Enterprise Linux 8 update for bind9.16
• Red Hat Enterprise Linux 9 update for bind
• Red Hat Enterprise Linux 8 update for bind
• openEuler 22.03 LTS SP4 update for bind
• openEuler 20.03 LTS SP4 update for bind
• Anolis OS update for bind
• Anolis OS update for bind9.16
• Red Hat Enterprise Linux 9 update for bind
• Multiple vulnerabilities in Red Hat OpenShift Container Platform 4.22
• Fedora 45 update for bind
• Fedora 44 update for bind
• Fedora 43 update for bind
• Red Hat Enterprise Linux 7 Extended Lifecycle Support update for bind
• Ubuntu update for bind9
• Denial of service in BIG-IP DNS