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Fencer Intel
high 7.5

CVE-2026-81563 json

SVCB AliasMode additional-data error leaks qpcache references

published last mo. modified 16d ago also EUVD-2026-80770

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups. 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.

Patch / fix

  • isc bind 9.20.29, 9.20.29-s1, 9.21.26
  • bind9 Debian 12 1:9.18.49-1~deb12u3
  • bind9 Debian 13 1:9.20.29-1~deb13u1
  • bind9 Debian 14 1:9.20.29-1

debian advisories DEBIAN-CVE-2026-81563

  • bind9 Ubuntu 22.04 LTS 1:9.18.39-0ubuntu0.22.04.7
  • bind9 Ubuntu 24.04 LTS 1:9.18.39-0ubuntu0.24.04.8
  • bind9 Ubuntu 26.10 1:9.20.24-1ubuntu3.1
  • bind9 Ubuntu 26.04 LTS 1:9.20.24-1ubuntu0.4
  • bind9 Ubuntu Pro 20.04 LTS 1:9.18.30-0ubuntu0.20.04.2+esm3

ubuntu advisories UBUNTU-CVE-2026-81563

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

  • bind9.18 RHEL 9 32:9.18.29-14.el9_8.10
  • bind9.18-libs RHEL 9 32:9.18.29-14.el9_8.10
  • bind9.18-utils RHEL 9 32:9.18.29-14.el9_8.10
  • bind9.18-chroot RHEL 9 32:9.18.29-14.el9_8.10
  • bind9.18-dnssec-utils RHEL 9 32:9.18.29-14.el9_8.10
  • bind RHEL 10.2 32:9.18.33-15.el10_2.12
  • bind-libs RHEL 10.2 32:9.18.33-15.el10_2.12
  • bind-utils RHEL 10.2 32:9.18.33-15.el10_2.12

red hat advisories RHSA-2026:75578RHSA-2026:75577RHSA-2026:68279

  • bind SLES for SAP applications 16.0, SLES 16.0 9.20.29-160000.1.1
  • bind SLE Module for Server Applications 15 SP7, SLE Module for Basesystem 15 SP7 9.20.29-150700.3.32.2
  • bind SLES for SAP 15 SP6, SLES 15 SP6-LTSS 9.18.50-150600.3.35.1

suse advisories SUSE-SU-2026:4608-1SUSE-SU-2026:24157-1SUSE-SU-2026:4285-1

  • bind openSUSE Leap 16.0 9.20.29-160000.1.1
  • bind openSUSE Tumbleweed 9.20.29-1.1

opensuse advisories openSUSE-SU-2026:22049-1openSUSE-SU-2026:11916-1

  • bind AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind-libs AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind-utils AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind-chroot AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind-license AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind-dnssec-utils AlmaLinux 10 32:9.18.33-15.el10_2.12
  • bind9.18 AlmaLinux 9 32:9.18.29-14.el9_8.10
  • bind9.18-libs AlmaLinux 9 32:9.18.29-14.el9_8.10

almalinux advisories ALSA-2026:75577ALSA-2026:75578

  • bind Rocky Linux 10 2:9.18.33-15.el10_2.12
  • bind9.18 Rocky Linux 9 2:9.18.29-14.el9_8.10

rocky linux advisories RLSA-2026:75577RLSA-2026:75578

  • bind Alpine 3.24, Alpine 3.23, Alpine 3.22 9.20.29-r0

alpine advisories ALPINE-CVE-2026-81563

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 9.20.30-1

azure linux advisories AZL-103347

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-2026-81563 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.

Check with Fencer

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-2026-81563 updated cvss 7.5

bind: BIND resolver: Denial of Service due to resource exhaustion in SVCB/HTTPS AliasMode processing

  • Red Hat CodeReady Linux Builder EUS (v.9.6) bind9.18-libs 9.18.29-4.el9_6.5
    fixed: vendor fix RHSA-2026:94278
  • Red Hat Enterprise Linux AppStream (v. 9) bind9.18 9.18.29-14.el9_8.10, bind9.18-libs 9.18.29-14.el9_8.10, bind9.18-utils 9.18.29-14.el9_8.10, bind9.18-chroot 9.18.29-14.el9_8.10, bind9.18-dnssec-utils 9.18.29-14.el9_8.10
    fixed: vendor fix RHSA-2026:75578
  • Red Hat Enterprise Linux AppStream (v. 10) bind 9.18.33-15.el10_2.12, bind-libs 9.18.33-15.el10_2.12, bind-utils 9.18.33-15.el10_2.12, bind-chroot 9.18.33-15.el10_2.12, bind-license 9.18.33-15.el10_2.12, bind-dnssec-utils 9.18.33-15.el10_2.12
    fixed: vendor fix RHSA-2026:75577
  • 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) bind9.18 9.18.29-4.el9_6.5, bind9.18-libs 9.18.29-4.el9_6.5
    fixed: vendor fix RHSA-2026:94278
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) bind9.18-libs 9.18.29-14.el9_8.10
    fixed: vendor fix RHSA-2026:75578
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) bind-doc 9.18.33-15.el10_2.12, bind-devel 9.18.33-15.el10_2.12, bind-debuginfo 9.18.33-15.el10_2.12, bind-debugsource 9.18.33-15.el10_2.12, bind-libs-debuginfo 9.18.33-15.el10_2.12, bind-utils-debuginfo 9.18.33-15.el10_2.12, +1 more
    fixed: vendor fix RHSA-2026:75577
  • Red Hat Hardened Images bind 9.20.29-0.1.hum1, bind-libs 9.20.29-0.1.hum1, bind-utils 9.20.29-0.1.hum1, bind-chroot 9.20.29-0.1.hum1, bind-dnssec-utils 9.20.29-0.1.hum1
    fixed: vendor fix RHSA-2026:68279
show 1 more
  • Red Hat CodeReady Linux Builder EUS (v.9.6) bind9.18-doc 9.18.29-4.el9_6.5, bind9.18-devel 9.18.29-4.el9_6.5, bind9.18-debuginfo 9.18.29-4.el9_6.5, bind9.18-debugsource 9.18.29-4.el9_6.5, bind9.18-libs-debuginfo 9.18.29-4.el9_6.5, bind9.18-utils-debuginfo 9.18.29-4.el9_6.5, +1 more 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, dhcp, bind-libs, bind-utils, dhcp-relay, bind-chroot, +6 more 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
    +4 more products
    Red Hat Enterprise Linux AppStream EUS (v.9.6) bind9.18-utils 9.18.29-4.el9_6.5, bind9.18-chroot 9.18.29-4.el9_6.5, bind9.18-dnssec-utils 9.18.29-4.el9_6.5 Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) bind-doc 9.18.33-4.el10_0.6, bind-devel 9.18.33-4.el10_0.6, bind-debuginfo 9.18.33-4.el10_0.6, bind-debugsource 9.18.33-4.el10_0.6, bind-libs-debuginfo 9.18.33-4.el10_0.6, bind-utils-debuginfo 9.18.33-4.el10_0.6, +1 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

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
last mo.

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% 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

Affected products

  • ISC BIND 9

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime

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.