CVE-2026-66374 Memory corruption in Knot Resolver
Remote attackers can execute arbitrary code on Knot Resolver servers via a heap-based buffer overflow in the DNS-over-QUIC receive path.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-66374?
CVE-2026-66374 is a high-severity memory corruption vulnerability in nic Knot Resolver, published on 25 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow in the DoQ (DNS-over-QUIC) receive path.
Weakness: CWE-1284
Which versions are affected by CVE-2026-66374?
How do I fix CVE-2026-66374?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-66374 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-66374 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as DEBIAN-CVE-2026-66374, GHSA-pw7g-jh5j-6w4m, UBUNTU-CVE-2026-66374.