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Vulnerability · Published Apr 17, 2026 · Assigned by redhat

CVE-2026-6507Dnsmasq: dnsmasq: denial of service due to out-of-bounds write in dhcp bootreply processing

High 7.5

In plain English

A high-severity out-of-bounds write in dnsmasq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 58.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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).

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:14dnsmasq2.92-4DEBIAN-CVE-2026-6507
Ubuntu:26.04:LTSdnsmasq2.92-1ubuntu0.3UBUNTU-CVE-2026-6507
Ubuntu:26.04:LTSdnsmasq2.92-1ubuntu0.3USN-8308-1

Affected products (as reported)

VendorProductVersions
dnsmasq 2.92 – before 2.93
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 4 see references

Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References