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Fencer Intel
high 7.3

CVE-2026-2291 json

CVE-2026-2291

published 5mo ago modified 3mo ago also EUVD-2026-29091

cvss
7.3
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 49%
public exploits
0
none known

Summary

dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS.

Patch / fix

  • dnsmasq dnsmasq 2.92rel2
  • dnsmasq Debian 12 2.90-4~deb12u2
  • dnsmasq Debian 13 2.91-1+deb13u1
  • dnsmasq Debian 14 2.92-5

debian advisories DEBIAN-CVE-2026-2291

  • dnsmasq Ubuntu 22.04 LTS 2.90-0ubuntu0.22.04.3
  • dnsmasq Ubuntu 24.04 LTS 2.90-2ubuntu0.3
  • dnsmasq Ubuntu 25.10 2.91-1ubuntu0.2
  • dnsmasq Ubuntu 26.04 LTS 2.92-1ubuntu0.2
  • dnsmasq Ubuntu Pro 14.04 LTS 2.68-1ubuntu0.2+esm5
  • dnsmasq Ubuntu Pro 16.04 LTS 2.90-0ubuntu0.16.04.1+esm3
  • dnsmasq Ubuntu Pro 18.04 LTS 2.90-0ubuntu0.18.04.1+esm3
  • dnsmasq Ubuntu Pro 20.04 LTS 2.90-0ubuntu0.20.04.1+esm2

ubuntu advisories UBUNTU-CVE-2026-2291

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

  • dnsmasq RHEL 8 2.79-36.el8_10
  • dnsmasq-utils RHEL 8 2.79-36.el8_10
  • dnsmasq RHEL 9 2.85-18.el9_8.1
  • dnsmasq-utils RHEL 9 2.85-18.el9_8.1
  • dnsmasq RHEL 10.2 2.90-7.el10_2
  • dnsmasq-utils RHEL 10.2 2.90-7.el10_2
  • dnsmasq RHEL 9.6 EUS 2.85-17.el9_6.1
  • dnsmasq-utils RHEL 9.6 EUS 2.85-17.el9_6.1

red hat advisories RHSA-2026:34508RHSA-2026:20589RHSA-2026:19373RHSA-2026:19158

  • dnsmasq Linux Micro 6.1 2.93-slfo.1.1_1.1
  • dnsmasq SLES for SAP applications 16.0, SLES 16.0 2.93-160000.1.1
  • dnsmasq SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.92rel2-18.27.1

suse advisories SUSE-SU-2026:22454-1SUSE-SU-2026:22496-1SUSE-SU-2026:2458-1

  • dnsmasq openSUSE Leap 16.0 2.93-160000.1.1
  • dnsmasq openSUSE Tumbleweed 2.92rel2-1.1

opensuse advisories openSUSE-SU-2026:21192-1openSUSE-SU-2026:10821-1

  • dnsmasq AlmaLinux 8 2.79-36.el8_10
  • dnsmasq-utils AlmaLinux 8 2.79-36.el8_10
  • dnsmasq AlmaLinux 10 2.90-7.el10_2
  • dnsmasq-utils AlmaLinux 10 2.90-7.el10_2
  • dnsmasq AlmaLinux 9 2.85-18.el9_8.1
  • dnsmasq-utils AlmaLinux 9 2.85-18.el9_8.1

almalinux advisories ALSA-2026:20589ALSA-2026:19158ALSA-2026:19373

  • dnsmasq Rocky Linux 10 2.90-7.el10_2
  • dnsmasq Rocky Linux 8 2.79-36.el8_10
  • dnsmasq Rocky Linux 9 2.85-18.el9_8.1

rocky linux advisories RLSA-2026:19158RLSA-2026:20589RLSA-2026:19373

  • dnsmasq Alpine 3.23, Alpine 3.22 2.91-r1
  • dnsmasq Alpine 3.24 2.92_p2-r0

alpine advisories ALPINE-CVE-2026-2291

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

  • dnsmasq Azure Linux 3.0 2.92-1

azure linux advisories AZL-86763

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-2026-2291 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-2026-2291 updated cvss 6.5

dnsmasq: dnsmasq: heap buffer overflow in cache via NAME_ESCAPE expansion

  • Red Hat Enterprise Linux 6 dnsmasq, dnsmasq-utils
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 dnsmasq, dnsmasq-utils Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    affected: no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) dnsmasq 2.79-36.el8_10, dnsmasq-utils 2.79-36.el8_10
    fixed: vendor fix RHSA-2026:20589
  • Red Hat Enterprise Linux AppStream (v. 9) dnsmasq 2.85-18.el9_8.1, dnsmasq-utils 2.85-18.el9_8.1
    fixed: vendor fix RHSA-2026:19373
  • Red Hat Enterprise Linux AppStream (v. 10) dnsmasq 2.90-7.el10_2, dnsmasq-utils 2.90-7.el10_2
    fixed: vendor fix RHSA-2026:19158
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) dnsmasq 2.79-21.el8_6.6
    fixed: vendor fix RHSA-2026:96241
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) dnsmasq 2.79-26.el8_8.5
    fixed: vendor fix RHSA-2026:96246
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) dnsmasq 2.85-6.el9_2.5
    fixed: vendor fix RHSA-2026:95093
show 7 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) dnsmasq 2.85-16.el9_4.1
    fixed: vendor fix RHSA-2026:95088
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) dnsmasq 2.90-4.el10_0.1
    fixed: vendor fix RHSA-2026:92677
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) dnsmasq 2.85-17.el9_6.1, dnsmasq-utils 2.85-17.el9_6.1
    fixed: vendor fix RHSA-2026:34508
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) dnsmasq 2.79-21.el8_6.6
    fixed: vendor fix RHSA-2026:96241
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) dnsmasq 2.79-26.el8_8.5
    fixed: vendor fix RHSA-2026:96246
  • Red Hat OpenShift Container Platform 4.19 rhcos 4.19.9.6.202608120446
    fixed: vendor fix RHSA-2026:54553
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) dnsmasq-utils 2.79-21.el8_6.6 Red Hat Enterprise Linux AppStream E4S (v.8.8) dnsmasq-utils 2.79-26.el8_8.5 Red Hat Enterprise Linux AppStream E4S (v.9.2) dnsmasq-utils 2.85-6.el9_2.5 Red Hat Enterprise Linux AppStream E4S (v.9.4) dnsmasq-utils 2.85-16.el9_4.1 Red Hat Enterprise Linux AppStream EUS (v. 10.0) dnsmasq-utils 2.90-4.el10_0.1 Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) dnsmasq-utils 2.79-21.el8_6.6
    +1 more products
    Red Hat Enterprise Linux AppStream TUS (v.8.8) dnsmasq-utils 2.79-26.el8_8.5
    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

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CNA 3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected products

  • dnsmasq dnsmasq

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.