Out-of-bounds write in Dnsmasq - CVE-2026-2291
Published: May 12, 2026
Vulnerability identifier: #VU131139
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-2291
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: GNU
Affected software:
Dnsmasq
Dnsmasq
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds write in struct bigname when processing DNS queries or DNS responses containing large domain names. A remote attacker can send a specially crafted DNS query or response to cause a denial of service.
How to mitigate CVE-2026-2291
Install security update from vendor's website.