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Fencer Vulns
high 7.5

CVE-2026-6507 json

Dnsmasq: dnsmasq: denial of service due to out-of-bounds write in dhcp bootreply processing

published 2026-04-17 6 mo ago modified 2026-11-05 3 d ago also EUVD-2026-23419

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

A flaw was found in dnsmasq. A remote attacker could exploit an out-of-bounds write vulnerability by sending a specially crafted BOOTREPLY (Bootstrap Protocol Reply) packet to a dnsmasq server configured with the `--dhcp-split-relay` option. This can lead to memory corruption, causing the dnsmasq daemon to crash and resulting in a denial of service (DoS).

Patch / fix

  • dnsmasq Debian 14 2.92-4

debian advisories DEBIAN-CVE-2026-6507

  • dnsmasq Ubuntu 26.04 LTS 2.92-1ubuntu0.3

ubuntu advisories UBUNTU-CVE-2026-6507

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 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 2.92-3.1

opensuse advisories openSUSE-SU-2026:21192-1openSUSE-SU-2026:10605-1

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-2026-6507 updated cvss 7.5

dnsmasq: dnsmasq: Denial of Service due to out-of-bounds write in DHCP BOOTREPLY processing

  • Red Hat Enterprise Linux 6 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 7 dnsmasq, dnsmasq-utils
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 dnsmasq, dnsmasq-utils
    not affected: component not present
  • Red Hat Enterprise Linux 9 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 10 dnsmasq 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
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% 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

  • 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 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.