CVE-2026-2291 CVE-2026-2291
Attackers can exploit a heap buffer overflow in dnsmasq to inject false DNS cache entries or cause a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-2291?
CVE-2026-2291 is a high-severity memory corruption vulnerability in dnsmasq, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS.
Which versions are affected by CVE-2026-2291?
How do I fix CVE-2026-2291?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-2291 being exploited?
There is no known exploitation of CVE-2026-2291 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as ALPINE-CVE-2026-2291, AZL-86763, BELL-CVE-2026-2291, CLEANSTART-2026-DR22797, DEBIAN-CVE-2026-2291, GHSA-hjxh-hmm9-wcmc and 5 more.