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Fencer Intel
high 7.5

CVE-2026-5946 json

Invalid handling of CLASS != IN

published 5mo ago modified last mo. also EUVD-2026-31107

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 32:9.18.33-15.el10_2.2
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 32:9.11.4-26.P2.el7_9.21
  • Red Hat Red Hat Enterprise Linux 8 32:9.11.36-16.el8_10.8, 32:9.16.23-0.22.el8_10.6
  • Red Hat Red Hat Enterprise Linux 9 32:9.16.23-40.el9_8.2, 32:9.18.29-14.el9_8.2
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 32:9.16.23-18.el9_4.12
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 32:9.16.23-31.el9_6.4
  • Red Hat Red Hat OpenShift Container Platform 4.16 416.94.202609011112-0
  • Red Hat Red Hat Hardened Images 9.18.49-1.hum1
  • bind9 Debian 12 1:9.18.49-1~deb12u2
  • bind9 Debian 13 1:9.20.23-1~deb13u1
  • bind9 Debian 14 1:9.20.23-1

debian advisories DEBIAN-CVE-2026-5946

  • bind9 Ubuntu 22.04 LTS 1:9.18.39-0ubuntu0.22.04.4
  • bind9 Ubuntu 24.04 LTS 1:9.18.39-0ubuntu0.24.04.5
  • bind9 Ubuntu 25.10 1:9.20.11-1ubuntu2.4
  • bind9 Ubuntu 26.04 LTS 1:9.20.18-1ubuntu2.1
  • bind9 Ubuntu Pro 18.04 LTS 1:9.11.3+dfsg-1ubuntu1.19+esm5
  • bind9 Ubuntu Pro 20.04 LTS 1:9.18.30-0ubuntu0.20.04.2+esm2

ubuntu advisories UBUNTU-CVE-2026-5946

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 RHEL 9 32:9.16.23-40.el9_8.2
  • bind-libs RHEL 9 32:9.16.23-40.el9_8.2
  • bind-utils RHEL 9 32:9.16.23-40.el9_8.2
  • bind-chroot RHEL 9 32:9.16.23-40.el9_8.2
  • bind-license RHEL 9 32:9.16.23-40.el9_8.2
  • python3-bind RHEL 9 32:9.16.23-40.el9_8.2
  • bind-dnssec-utils RHEL 9 32:9.16.23-40.el9_8.2
  • bind9.18 RHEL 9 32:9.18.29-14.el9_8.2

red hat advisories RHSA-2026:79160RHSA-2026:60383RHSA-2026:57189RHSA-2026:55441RHSA-2026:24367RHSA-2026:24368

  • bind Multi Linux Manager Tools SLE-Micro-5, Manager Client Tools for SLE Micro 5 9.16.6-150000.12.91.1
  • bind SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Basesystem 15 SP7 9.16.6-150300.22.59.1
  • bind SLE Module for Server Applications 15 SP7, SLE Module for Basesystem 15 SP7 9.20.23-150700.3.25.1
  • bind SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 9.16.50-150400.5.62.1
  • bind SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 9.16.50-150500.8.38.1
  • bind SLES for SAP applications 16.0, SLES 16.0 9.20.23-160000.1.1
  • bind SLES for SAP 15 SP6, SLES 15 SP6-LTSS 9.18.49-150600.3.26.1

suse advisories SUSE-SU-2026:3517-1SUSE-SU-2026:2779-1SUSE-SU-2026:2673-1SUSE-SU-2026:2676-1SUSE-SU-2026:2617-1SUSE-SU-2026:2616-1

  • bind openSUSE Leap 16.0 9.20.23-160000.1.1
  • bind openSUSE Tumbleweed 9.20.23-1.1

opensuse advisories openSUSE-SU-2026:21123-1openSUSE-SU-2026:10874-1

  • bind AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind-libs AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind-utils AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind-chroot AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind-license AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind-dnssec-utils AlmaLinux 10 32:9.18.33-15.el10_2.2
  • bind AlmaLinux 8 32:9.11.36-16.el8_10.8
  • bind-sdb AlmaLinux 8 32:9.11.36-16.el8_10.8

almalinux advisories ALSA-2026:24338ALSA-2026:24339ALSA-2026:24367ALSA-2026:24368ALSA-2026:23360

  • bind Rocky Linux 10 2:9.18.33-15.el10_2.2
  • bind Rocky Linux 9 2:9.16.23-40.el9_8.2
  • bind9.18 Rocky Linux 9 2:9.18.29-14.el9_8.2
  • bind Rocky Linux 8 2:9.11.36-16.el8_10.8
  • bind9.16 Rocky Linux 8 2:9.16.23-0.22.el8_10.6

rocky linux advisories RLSA-2026:24338RLSA-2026:24367RLSA-2026:24368RLSA-2026:24339RLSA-2026:23360

  • bind Alpine 3.21, Alpine 3.20 9.18.49-r0
  • bind Alpine 3.24, Alpine 3.23, Alpine 3.22 9.20.23-r0

alpine advisories ALPINE-CVE-2026-5946

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 9.20.23-1

azure linux advisories AZL-87096

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

Is CVE-2026-5946 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-5946 updated cvss 7.5

bind: BIND: Denial of Service via specially crafted DNS messages

  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.6) bind-libs 9.16.23-31.el9_6.4, bind9.18-libs 9.18.29-4.el9_6.5
    fixed: vendor fix RHSA-2026:55441
  • Red Hat Enterprise Linux AppStream (v. 8) bind 9.11.36-16.el8_10.8, bind-sdb 9.11.36-16.el8_10.8, bind-libs 9.11.36-16.el8_10.8, bind-utils 9.11.36-16.el8_10.8, bind9.16 9.16.23-0.22.el8_10.6, bind-chroot 9.11.36-16.el8_10.8, +13 more
    fixed: vendor fix RHSA-2026:24339
  • Red Hat Enterprise Linux AppStream (v. 9) bind 9.16.23-40.el9_8.2, bind9.18 9.18.29-14.el9_8.2, bind-libs 9.16.23-40.el9_8.2, bind-utils 9.16.23-40.el9_8.2, bind-chroot 9.16.23-40.el9_8.2, bind-license 9.16.23-40.el9_8.2, +6 more
    fixed: vendor fix RHSA-2026:24367
  • Red Hat Enterprise Linux AppStream (v. 10) bind 9.18.33-15.el10_2.2, bind-libs 9.18.33-15.el10_2.2, bind-utils 9.18.33-15.el10_2.2, bind-chroot 9.18.33-15.el10_2.2, bind-license 9.18.33-15.el10_2.2, bind-dnssec-utils 9.18.33-15.el10_2.2
    fixed: vendor fix RHSA-2026:24338
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) bind 9.11.26-4.el8_4.10, bind-sdb 9.11.26-4.el8_4.10, bind-libs 9.11.26-4.el8_4.10, bind-utils 9.11.26-4.el8_4.10, bind-pkcs11 9.11.26-4.el8_4.10, bind-libs-lite 9.11.26-4.el8_4.10, +2 more
    fixed: vendor fix RHSA-2026:95477
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) bind 9.11.36-3.el8_6.13, bind-sdb 9.11.36-3.el8_6.13, bind-libs 9.11.36-3.el8_6.13, bind-utils 9.11.36-3.el8_6.13, bind9.16 9.16.23-0.7.el8_6.12, bind-chroot 9.11.36-3.el8_6.13, +8 more
    fixed: vendor fix RHSA-2026:95435
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) bind 9.11.36-8.el8_8.11, bind-sdb 9.11.36-8.el8_8.11, bind-utils 9.11.36-8.el8_8.11, bind9.16 9.16.23-0.14.el8_8.9, bind-pkcs11 9.11.36-8.el8_8.11, bind-libs-lite 9.11.36-8.el8_8.11, +3 more
    fixed: vendor fix RHSA-2026:95478
show 28 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) bind 9.16.23-11.el9_2.12, bind-libs 9.16.23-11.el9_2.12
    fixed: vendor fix RHSA-2026:95242
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) bind 9.16.23-18.el9_4.12, bind-libs 9.16.23-18.el9_4.12, bind-utils 9.16.23-18.el9_4.12, bind-chroot 9.16.23-18.el9_4.12, bind-license 9.16.23-18.el9_4.12, python3-bind 9.16.23-18.el9_4.12, +1 more
    fixed: vendor fix RHSA-2026:57189
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) bind 9.18.33-4.el10_0.6, bind-libs 9.18.33-4.el10_0.6
    fixed: vendor fix RHSA-2026:94115
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) bind 9.16.23-31.el9_6.4, bind9.18 9.18.29-4.el9_6.5, bind-libs 9.16.23-31.el9_6.4, bind9.18-libs 9.18.29-4.el9_6.5
    fixed: vendor fix RHSA-2026:55441
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) bind 9.11.26-4.el8_4.10, bind-sdb 9.11.26-4.el8_4.10, bind-libs 9.11.26-4.el8_4.10, bind-utils 9.11.26-4.el8_4.10, bind-pkcs11 9.11.26-4.el8_4.10, bind-libs-lite 9.11.26-4.el8_4.10, +2 more
    fixed: vendor fix RHSA-2026:95477
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) bind 9.11.36-3.el8_6.13, bind-sdb 9.11.36-3.el8_6.13, bind-libs 9.11.36-3.el8_6.13, bind-utils 9.11.36-3.el8_6.13, bind9.16 9.16.23-0.7.el8_6.12, bind-chroot 9.11.36-3.el8_6.13, +8 more
    fixed: vendor fix RHSA-2026:95435
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) bind 9.11.36-8.el8_8.11, bind-sdb 9.11.36-8.el8_8.11, bind-utils 9.11.36-8.el8_8.11, bind9.16 9.16.23-0.14.el8_8.9, bind-pkcs11 9.11.36-8.el8_8.11, bind-libs-lite 9.11.36-8.el8_8.11, +3 more
    fixed: vendor fix RHSA-2026:95478
  • Red Hat Enterprise Linux BaseOS (v. 8) bind 9.11.36-16.el8_10.8, bind-export-libs 9.11.36-16.el8_10.8
    fixed: vendor fix RHSA-2026:24339
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bind 9.11.26-4.el8_4.10, bind-export-libs 9.11.26-4.el8_4.10
    fixed: vendor fix RHSA-2026:95477
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bind 9.11.36-3.el8_6.13, bind-export-libs 9.11.36-3.el8_6.13
    fixed: vendor fix RHSA-2026:95435
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bind 9.11.36-8.el8_8.11, bind-export-libs 9.11.36-8.el8_8.11
    fixed: vendor fix RHSA-2026:95478
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bind 9.11.26-4.el8_4.10, bind-export-libs 9.11.26-4.el8_4.10
    fixed: vendor fix RHSA-2026:95477
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bind 9.11.36-3.el8_6.13, bind-export-libs 9.11.36-3.el8_6.13
    fixed: vendor fix RHSA-2026:95435
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bind 9.11.36-8.el8_8.11, bind-export-libs 9.11.36-8.el8_8.11
    fixed: vendor fix RHSA-2026:95478
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) bind-libs 9.16.23-40.el9_8.2, bind9.18-libs 9.18.29-14.el9_8.2
    fixed: vendor fix RHSA-2026:24367
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) bind-doc 9.18.33-15.el10_2.2, bind-devel 9.18.33-15.el10_2.2, bind-debuginfo 9.18.33-15.el10_2.2, bind-debugsource 9.18.33-15.el10_2.2, bind-libs-debuginfo 9.18.33-15.el10_2.2, bind-utils-debuginfo 9.18.33-15.el10_2.2, +1 more
    fixed: vendor fix RHSA-2026:24338
  • Red Hat Enterprise Linux CRB (v. 8) bind9.16-libs 9.16.23-0.22.el8_10.6
    fixed: vendor fix RHSA-2026:23360
  • Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION) bind 9.8.2-0.68.rc1.el6_10.20, bind-libs 9.8.2-0.68.rc1.el6_10.20
    fixed: vendor fix RHSA-2026:95727
  • Red Hat Enterprise Linux Server (v. 7 ELS) bind 9.11.4-26.P2.el7_9.21, bind-pkcs11 9.11.4-26.P2.el7_9.21, bind-libs-lite 9.11.4-26.P2.el7_9.21, bind-export-libs 9.11.4-26.P2.el7_9.21, bind-pkcs11-libs 9.11.4-26.P2.el7_9.21
    fixed: vendor fix RHSA-2026:60383
  • Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION) bind-sdb 9.8.2-0.68.rc1.el6_10.20
    fixed: vendor fix RHSA-2026:95727
  • Red Hat Enterprise Linux Server Optional (v. 7 ELS) bind-sdb 9.11.4-26.P2.el7_9.21
    fixed: vendor fix RHSA-2026:60383
  • Red Hat Hardened Images bind 9.18.49-1.hum1, bind-libs 9.18.49-1.hum1, bind-utils 9.18.49-1.hum1, bind-chroot 9.18.49-1.hum1, bind-dnssec-utils 9.18.49-1.hum1
    fixed: vendor fix RHSA-2026:20334
  • Red Hat OpenShift Container Platform 4.16 rhcos 416.94.202609011112
    fixed: vendor fix RHSA-2026:62549
  • Red Hat OpenShift Container Platform 4.17 rhcos 417.94.202609191027
    fixed: vendor fix RHSA-2026:70586
  • Red Hat OpenShift Container Platform 4.18 rhcos 418.94.202609031320, rhcos 418.94.202609171815
    fixed: vendor fix RHSA-2026:65851
  • Red Hat CodeReady Linux Builder EUS (v.9.6) bind-doc 9.16.23-31.el9_6.4, bind-devel 9.16.23-31.el9_6.4, bind9.18-doc 9.18.29-4.el9_6.5, bind9.18-devel 9.18.29-4.el9_6.5, bind-debuginfo 9.16.23-31.el9_6.4, bind-debugsource 9.16.23-31.el9_6.4, +8 more
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 9 dhcp, dhcp-relay, dhcp-client, dhcp-common, dhcp-server
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) bind-chroot 9.11.26-4.el8_4.10, bind-license 9.11.26-4.el8_4.10, python3-bind 9.11.26-4.el8_4.10, bind-sdb-chroot 9.11.26-4.el8_4.10 Red Hat Enterprise Linux AppStream AUS (v.8.6) bind9.16-utils 9.16.23-0.7.el8_6.12, bind9.16-chroot 9.16.23-0.7.el8_6.12, bind9.16-license 9.16.23-0.7.el8_6.12 Red Hat Enterprise Linux AppStream E4S (v.8.8) bind-libs 9.11.36-8.el8_8.11, bind-chroot 9.11.36-8.el8_8.11, bind-license 9.11.36-8.el8_8.11, python3-bind 9.11.36-8.el8_8.11, bind-sdb-chroot 9.11.36-8.el8_8.11, bind9.16-utils 9.16.23-0.14.el8_8.9, +4 more Red Hat Enterprise Linux AppStream E4S (v.9.2) bind-utils 9.16.23-11.el9_2.12, bind-chroot 9.16.23-11.el9_2.12, bind-license 9.16.23-11.el9_2.12, python3-bind 9.16.23-11.el9_2.12, bind-dnssec-utils 9.16.23-11.el9_2.12 Red Hat Enterprise Linux AppStream EUS (v. 10.0) bind-utils 9.18.33-4.el10_0.6, bind-chroot 9.18.33-4.el10_0.6, bind-license 9.18.33-4.el10_0.6, bind-dnssec-utils 9.18.33-4.el10_0.6
    not affected: vulnerable code not present

13 more not affected in the full advisory

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
5mo ago

Exploit prediction

1.94% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-11).

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
CISA ADP 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
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat OpenShift Container Platform 4.16
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-20 Improper Input Validation
  • CWE-125 Out-of-bounds Read
  • CWE-617 Reachable Assertion
  • CWE-754 Improper Check for Unusual or Exceptional Conditions
  • CWE-843 Access of Resource Using Incompatible Type
  • CWE-1287 Improper Validation of Specified Type of Input

References

Sources

Fencer Intel 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.