CVE-2026-4891: CVE-2026-4891

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 6.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-11 · updated 2026-08-25
Weakness: CWE-125

Description

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.

Affected products

dnsmasq: before 2.92rel2 — fixed in 2.92rel2

How to fix

Upgrade to a fixed version: dnsmasq 2.92rel2. Check the vendor advisory for mitigations.

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

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