CVE-2026-5172

critical

Description

A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger a heap out-of-bounds read and crash by exploiting a malformed DNS response, enabling extract_name() to advance the pointer past the record’s end.

References

https://kb.cert.org/vuls/id/471747

https://www.kb.cert.org/vuls/id/471747

https://thekelleys.org.uk/dnsmasq/CVE/

https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html

https://github.com/pi-hole/FTL/releases/tag/v6.6.2

https://github.com/NixOS/nixpkgs/pull/519093

https://github.com/NixOS/nixpkgs/pull/519082

Details

Source: Mitre, NVD

Published: 2026-05-11

Updated: 2026-05-12

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.0003