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Fencer Vulns
high 7.5

CVE-2026-81563 json

SVCB AliasMode additional-data error leaks qpcache references

published 2026-09-16 54 d ago modified 2026-10-26 13 d 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

  • 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

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
52 d ago

Exploit prediction

0.57% chance of exploitation in the next 30 days, higher than 47% 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-401 Missing Release of Memory after Effective Lifetime

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.