CVE-2026-4891

A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

Score

CVSS 3.1 7.5 High

Status

Awaiting Analysis - cret@cert.org

Published

2026-05-11

Last modified

2026-09-01

Weaknesses

CWE-125

Affected products

• Dnsmasq (Dnsmasq)
• Enterprise Linux (Redhat)
• Openshift (Redhat)
• Rhel Eus (Redhat)

References

• https://github.com/NixOS/nixpkgs/pull/519082
• https://github.com/NixOS/nixpkgs/pull/519093
• https://github.com/pi-hole/FTL/releases/tag/v6.6.2
• https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
• https://thekelleys.org.uk/dnsmasq/CVE/
• https://www.kb.cert.org/vuls/id/471747
• https://access.redhat.com/errata/RHSA-2026:19158
• https://access.redhat.com/errata/RHSA-2026:19373
• https://access.redhat.com/errata/RHSA-2026:20589
• https://access.redhat.com/errata/RHSA-2026:34508
• https://access.redhat.com/errata/RHSA-2026:40762
• https://access.redhat.com/security/cve/CVE-2026-4891
• https://bugzilla.redhat.com/show_bug.cgi?id=2458517
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4891.json