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Fencer Intel
high 7.4

CVE-2026-3593 json

Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation

published 5mo ago modified 2mo ago also EUVD-2026-31108

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation. This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1. BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Patch / fix

  • ISC BIND 9 9.18.0, 9.18.11-S1
  • Red Hat Red Hat Hardened Images 9.18.48-1.1.hum1
  • bind9 Debian 13 1:9.20.23-1~deb13u1
  • bind9 Debian 14 1:9.20.23-1

debian advisories DEBIAN-CVE-2026-3593

  • bind9 Ubuntu 25.10 1:9.20.11-1ubuntu2.4
  • bind9 Ubuntu 26.04 LTS 1:9.20.18-1ubuntu2.1

ubuntu advisories UBUNTU-CVE-2026-3593

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 9.18.48-1.1.hum1
  • bind-libs hummingbird 1 9.18.48-1.1.hum1
  • bind-utils hummingbird 1 9.18.48-1.1.hum1
  • bind-chroot hummingbird 1 9.18.48-1.1.hum1
  • bind-dnssec-utils hummingbird 1 9.18.48-1.1.hum1

red hat advisories RHSA-2026:7412

  • 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 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-2026:2673-1SUSE-SU-2026:2676-1SUSE-SU-2026:22198-1

  • bind openSUSE Leap 16.0 9.20.23-160000.1.1
  • bind openSUSE Tumbleweed 9.20.23-2.1

opensuse advisories openSUSE-SU-2026:21123-1openSUSE-SU-2026:10915-1

  • 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-2026-3593

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-87093

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-2026-3593 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-2026-3593 updated cvss 7.4

bind: Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation

  • Red Hat Hardened Images bind 9.18.48-1.1.hum1, bind-libs 9.18.48-1.1.hum1, bind-utils 9.18.48-1.1.hum1, bind-chroot 9.18.48-1.1.hum1, bind-dnssec-utils 9.18.48-1.1.hum1
    fixed: vendor fix RHSA-2026:7412
  • 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, bind9.18, bind-libs, bind-utils, dhcp-relay, +11 more Red Hat Enterprise Linux 10 bind Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, 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
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
CISA ADP 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • ISC BIND 9
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness

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.