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Fencer Vulns
high 7.5

CVE-2026-11605 json

Unnecessary validation of DNSSEC signed records

published 2026-07-22 3 mo ago modified 2026-11-02 6 d ago also EUVD-2026-47707

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits
0
none known

Summary

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.

Patch / fix

  • isc bind 9.20.26, 9.21.24
  • bind9 Debian 12 1:9.18.49-1~deb12u2
  • bind9 Debian 13 1:9.20.26-1~deb13u1
  • bind9 Debian 14 1:9.20.26-1

debian advisories DEBIAN-CVE-2026-11605

  • bind9 Ubuntu 26.04 LTS 1:9.20.24-1ubuntu0.2

ubuntu advisories UBUNTU-CVE-2026-11605

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bind hummingbird 1 9.18.50-22.hum1
  • bind-libs hummingbird 1 9.18.50-22.hum1
  • bind-utils hummingbird 1 9.18.50-22.hum1
  • bind-chroot hummingbird 1 9.18.50-22.hum1
  • bind-dnssec-utils hummingbird 1 9.18.50-22.hum1

red hat advisories RHSA-2026:42853

  • bind SLE Module for Server Applications 15 SP7, SLE Module for Basesystem 15 SP7 9.20.26-150700.3.29.1

suse advisories SUSE-SU-2026:3426-1

  • bind openSUSE Leap 16.0 9.20.26-160000.1.1
  • bind openSUSE Tumbleweed 9.20.26-1.1

opensuse advisories openSUSE-SU-2026:21489-1openSUSE-SU-2026:11375-1

  • bind Alpine 3.24, Alpine 3.23, Alpine 3.22 9.20.26-r0

alpine advisories ALPINE-CVE-2026-11605

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bind Azure Linux 3.0 9.20.26-1

azure linux advisories AZL-93126

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-11605 updated cvss 7.5

bind: bind9: Unnecessary validation of DNSSEC signed records

  • Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available
  • Red Hat Enterprise Linux 9 dhcp, dhcp-relay, dhcp-client, dhcp-common, dhcp-server
    under investigation
  • Red Hat Hardened Images bind 9.18.50-22.hum1, bind-libs 9.18.50-22.hum1, bind-utils 9.18.50-22.hum1, bind-chroot 9.18.50-22.hum1, bind-dnssec-utils 9.18.50-22.hum1
    fixed: vendor fix RHSA-2026:42853
  • Red Hat Enterprise Linux 6 bind, bind-sdb, bind-libs, bind-utils, bind-chroot Red Hat Enterprise Linux 7 bind, bind-sdb, bind-libs, bind-utils, bind-chroot, bind-pkcs11, +6 more Red Hat Enterprise Linux 8 bind, bind-sdb, bind9.16, bind-libs, bind-utils, bind-chroot, +14 more Red Hat Enterprise Linux 9 bind, bind9.18, bind-libs, bind-utils, bind-chroot, bind-license, +6 more Red Hat Enterprise Linux 10 bind
    not affected: vulnerable code not present
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: vulnerable code not in execute path

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.67% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • ISC BIND 9

Classification

Weakness
  • CWE-408 Incorrect Behavior Order: Early Amplification

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.