CVE-2026-81736

EUVD-2026-80740
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
iscCNA
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 47.12%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
iscbind
9.18.0 ≤
𝑥
≤ 9.18.50
CNA
iscbind
9.20.0 ≤
𝑥
≤ 9.20.27
CNA
iscbind
9.21.0 ≤
𝑥
≤ 9.21.25
CNA
Debian logo
Debian Releases
Debian Product
Codename
bind9
bookworm
vulnerable
bookworm (security)
1:9.18.49-1~deb12u3
fixed
forky
1:9.20.30-1
fixed
sid
1:9.20.30-1
fixed
trixie
vulnerable
trixie (security)
1:9.20.30-1~deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
bind9
bionic
not-affected
focal
Fixed in 1:9.18.30-0ubuntu0.20.04.2+esm3
released
jammy
Fixed in 1:9.18.39-0ubuntu0.22.04.7
released
noble
Fixed in 1:9.18.39-0ubuntu0.24.04.8
released
resolute
Fixed in 1:9.20.24-1ubuntu0.4
released
stonking
needed
trusty
not-affected
xenial
not-affected
isc-dhcp
bionic
needs-triage
focal
not-affected
jammy
not-affected
noble
needs-triage
resolute
needs-triage
stonking
dne
trusty
not-affected
xenial
not-affected
bind9-libs
focal
needs-triage
jammy
needs-triage
noble
dne
resolute
dne
stonking
dne
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
bind
suse enterprise sap 15 SP6
9.18.50-150600.3.35.1
fixed
suse enterprise sap 15 SP7
9.20.29-150700.3.32.2
fixed
suse enterprise server 15 SP6
9.18.50-150600.3.35.1
fixed
suse enterprise server 15 SP7
9.20.29-150700.3.32.2
fixed
bind-doc
suse enterprise sap 15 SP6
9.18.50-150600.3.35.1
fixed
suse enterprise sap 15 SP7
9.20.29-150700.3.32.2
fixed
suse enterprise server 15 SP6
9.18.50-150600.3.35.1
fixed
suse enterprise server 15 SP7
9.20.29-150700.3.32.2
fixed
bind-utils
suse enterprise sap 15 SP6
9.18.50-150600.3.35.1
fixed
suse enterprise server 15 SP6
9.18.50-150600.3.35.1
fixed
Red Hat logo
Red Hat Enterprise Linux Releases
Red Hat Product
Release
bind9.18
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-chroot
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-devel
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-dnssec-utils
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-doc
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-libs
RHEL 9
32:9.18.29-14.el9_8.10
fixed
bind9.18-utils
RHEL 9
32:9.18.29-14.el9_8.10
fixed
Amazon Linux logo
Amazon Linux Releases
Amazon Package
Release
bind
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-chroot
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-debuginfo
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-debugsource
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-devel
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-dnssec-utils
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-dnssec-utils-debuginfo
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-doc
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-libs
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-libs-debuginfo
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-license
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-utils
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
bind-utils-debuginfo
Amazon Linux 2023
32:9.18.50-1.amzn2023.0.3
fixed
Azure Linux logo
Azure Linux Releases
Azure Package
Release
bind
Azure Linux 3.0
0:9.20.30-1.azl3
fixed
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://downloads.isc.org/isc/bind9/9.20.29
https://downloads.isc.org/isc/bind9/9.21.26
https://kb.isc.org/docs/cve-2026-81736