Use-after-free in ISC BIND - CVE-2026-19666

Vulnerability identifier: #VU150225

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-2026-19666

CWE-ID: CWE-416

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 use-after-free in query_addnoqnameproof() via the DNS64 filter64 path when processing a malformed applicable answer from an authoritative server. A remote attacker can send a malformed applicable DNS answer to cause a denial of service.

Only resolvers configured to use dns64 are affected.

ISC BIND
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP4
Debian Linux
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Multi-Linux Manager Client Tools for SLE Micro
SUSE Linux Enterprise Micro
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Anolis OS
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Ubuntu
Basesystem Module
Server Applications Module
openSUSE Leap
Fedora
bind9 (Ubuntu package)
bind-debuginfo
libdns1110-debuginfo
libisccc161-debuginfo
bind-utils
libdns1110
libbind9-161-debuginfo
libbind9-161
libisccfg163-debuginfo
bind-utils-debuginfo
bind
bind-devel
libisccfg163
bind-debugsource
liblwres161-debuginfo
bind-doc
python-bind
libisc1107-32bit
libisc1107
libirs161-debuginfo
bind-chrootenv
liblwres161
libisc1107-debuginfo
libirs161
libisccc161
libisc1107-debuginfo-32bit
bind (Red Hat package) main
bind-chroot
bind-export-devel
bind-export-libs
bind-libs
bind-libs-lite
bind-lite-devel
bind-pkcs11
bind-pkcs11-devel
bind-pkcs11-libs
bind-pkcs11-utils
bind-sdb
bind-sdb-chroot
bind-license
python3-bind
libisc1606-debuginfo
libbind9-1600-debuginfo
libisccc1600-debuginfo
libisccc1600
libns1604-debuginfo
libirs1601
libisccfg1600
libns1604
libdns1605-debuginfo
libirs1601-debuginfo
libisc1606
libbind9-1600
libisccfg1600-debuginfo
libdns1605
libirs-devel
bind9.16-chroot
python3-bind9.16
bind9.16-license
bind9.16-doc
bind9.16-utils
bind9.16-libs
bind9.16-dnssec-utils
bind9.16-devel
bind9.16
bind-dnssec-utils
bind-dnssec-doc
bind9-next
bind-dyndb-ldap
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-debuginfo - addressed in versions 9.11.22-3.77.1, 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
libdns1110-debuginfo - update to 9.11.22-3.77.1
libisccc161-debuginfo - update to 9.11.22-3.77.1
bind-utils - addressed in versions 9.11.22-3.77.1, 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
libdns1110 - update to 9.11.22-3.77.1
libbind9-161-debuginfo - update to 9.11.22-3.77.1
libbind9-161 - update to 9.11.22-3.77.1
libisccfg163-debuginfo - update to 9.11.22-3.77.1
bind-utils-debuginfo - addressed in versions 9.11.22-3.77.1, 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
bind - addressed in versions 9.11.22-3.77.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
bind-devel - addressed in versions 9.11.22-3.77.1, 9.16.6-150300.22.65.1
libisccfg163 - update to 9.11.22-3.77.1
bind-debugsource - addressed in versions 9.11.22-3.77.1, 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
liblwres161-debuginfo - update to 9.11.22-3.77.1
bind-doc - addressed in versions 9.11.22-3.77.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1, 9.20.29-150700.3.32.2
python-bind - update to 9.11.22-3.77.1
libisc1107-32bit - update to 9.11.22-3.77.1
libisc1107 - update to 9.11.22-3.77.1
libirs161-debuginfo - update to 9.11.22-3.77.1
bind-chrootenv - addressed in versions 9.11.22-3.77.1, 9.16.6-150300.22.65.1
liblwres161 - update to 9.11.22-3.77.1
libisc1107-debuginfo - update to 9.11.22-3.77.1
libirs161 - update to 9.11.22-3.77.1
libisccc161 - update to 9.11.22-3.77.1
libisc1107-debuginfo-32bit - update to 9.11.22-3.77.1
bind (Red Hat package) main - addressed in versions 9.11.36-16.el8_10.16, 9.16.23-40.el9_8.10
bind - addressed in versions 9.11.36-16.0.1, 9.20.29-1
bind-chroot - addressed in versions 9.11.36-16.0.1, 9.20.29-1
bind-devel - addressed in versions 9.11.36-16.0.1, 9.20.29-1
bind-export-devel - update to 9.11.36-16.0.1
bind-export-libs - update to 9.11.36-16.0.1
bind-libs - addressed in versions 9.11.36-16.0.1, 9.20.29-1
bind-libs-lite - update to 9.11.36-16.0.1
bind-lite-devel - update to 9.11.36-16.0.1
bind-pkcs11 - update to 9.11.36-16.0.1
bind-pkcs11-devel - update to 9.11.36-16.0.1
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, 9.20.29-1
bind-license - addressed in versions 9.11.36-16.0.1, 9.20.29-1
python3-bind - update to 9.11.36-16.0.1
python3-bind - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1, 9.16.50-150400.5.70.1, 9.16.50-150500.8.46.1
libisc1606-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libbind9-1600-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libisccc1600-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libisccc1600 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libns1604-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libirs1601 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libisccfg1600 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libns1604 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libdns1605-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libirs1601-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libisc1606 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libbind9-1600 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libisccfg1600-debuginfo - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libdns1605 - addressed in versions 9.16.6-150000.12.94.1, 9.16.6-150300.22.65.1
libirs-devel - update to 9.16.6-150300.22.65.1
bind9.16-chroot - update to 9.16.23-0.22
python3-bind9.16 - update to 9.16.23-0.22
bind9.16-license - update to 9.16.23-0.22
bind9.16-doc - update to 9.16.23-0.22
bind9.16-utils - update to 9.16.23-0.22
bind9.16-libs - update to 9.16.23-0.22
bind9.16-dnssec-utils - update to 9.16.23-0.22
bind9.16-devel - update to 9.16.23-0.22
bind9.16 - update to 9.16.23-0.22
bind - addressed in versions 9.18.51^git20261003.d0a87358-2.fc43, 9.18.51^git20261003.d0a87358-2.fc44, 9.18.51^git20261003.d0a87358-11.fc46
bind-dnssec-utils - update to 9.20.29-1
bind-dnssec-doc - update to 9.20.29-1
bind-doc - update to 9.20.29-1
bind9-next - addressed in versions 9.21.26-1.fc43, 9.21.26-1.fc44, 9.21.26-1.fc45
bind-dyndb-ldap - addressed in versions 11.11-15.fc43, 11.11-17.fc44, 11.11-18.fc46
bind9 (Debian package) - update to 1:9.20.29-1~deb13u1

• https://kb.isc.org/docs/cve-2026-19666

• Multiple vulnerabilities in ISC BIND
• Debian update for bind9
• SUSE update for bind
• Red Hat Enterprise Linux 9 update for bind
• Red Hat Enterprise Linux 8 update for bind
• Anolis OS update for bind
• SUSE update for bind
• Fedora 45 update for bind9-next
• Fedora 44 update for bind9-next
• Fedora 43 update for bind9-next
• Fedora 43 update for bind, bind-dyndb-ldap
• Fedora 44 update for bind, bind-dyndb-ldap
• Fedora 46 update for bind, bind-dyndb-ldap
• Anolis OS update for bind9.16
• Anolis OS update for bind
• SUSE update for bind
• SUSE update for bind
• SUSE update for bind
• Ubuntu update for bind9
• SUSE update for bind