CVE-2026-4892: dnsmasq Heap-based Buffer Overflow

Vulnerability summary

CVE-2026-4892 is a high (CVSS 8.4) Heap-based Buffer Overflow vulnerability in dnsmasq. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 21.9% of scored vulnerabilities.

Timeline

1. 11-05-2026
   PublishedVulnerability first disclosed.
2. 01-09-2026
   Last modifiedVulnerability information updated.

Description

A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq allows local attackers to execute arbitrary code with root privileges via a crafted DHCPv6 packet.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().