CVE-2026-11605

EUVD-2026-47707
The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time.
This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
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
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 43.22%
Debian logo
Debian Releases
Debian Product
Codename
bind9
bookworm
vulnerable
bookworm (security)
1:9.18.49-1~deb12u2
fixed
forky
1:9.20.27-1
fixed
sid
1:9.20.27-2
fixed
trixie
vulnerable
trixie (security)
1:9.20.26-1~deb13u1
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
bind9
bionic
not-affected
focal
not-affected
jammy
not-affected
noble
not-affected
resolute
Fixed 1:9.20.24-1ubuntu0.2
released
trusty
not-affected
xenial
not-affected
isc-dhcp
bionic
not-affected
focal
not-affected
jammy
not-affected
noble
not-affected
resolute
not-affected
trusty
not-affected
xenial
not-affected
bind9-libs
focal
not-affected
jammy
not-affected
noble
dne
resolute
dne
openSUSE logo
openSUSE / SLES Releases
openSUSE Product
Release
bind
suse enterprise sap 15 SP7
9.20.26-150700.3.29.1
fixed
suse enterprise server 15 SP7
9.20.26-150700.3.29.1
fixed
bind-doc
suse enterprise sap 15 SP7
9.20.26-150700.3.29.1
fixed
suse enterprise server 15 SP7
9.20.26-150700.3.29.1
fixed
Azure Linux logo
Azure Linux Releases
Azure Package
Release
bind
Azure Linux 3.0
0:9.20.26-1.azl3
fixed
Common Weakness Enumeration
References
https://downloads.isc.org/isc/bind9/9.20.26
https://downloads.isc.org/isc/bind9/9.21.24
https://kb.isc.org/docs/cve-2026-11605