CVE-2026-66374 is a high-severity vulnerability in nic's Knot Resolver DNS software, specifically affecting versions prior to 6.4.1. The issue is a heap-based buffer overflow triggered in the DoQ receive path due to improper validation of input quantities (CWE-1284). This flaw can lead to remote code execution with no privileges or user interaction required. The CVSS 3.1 vector indicates network attack vector, high attack complexity, no privileges required, no user interaction, and a scope change with low confidentiality impact, high integrity impact, and low availability impact. No patch or official remediation level has been published yet.

Successful exploitation of this vulnerability allows an unauthenticated remote attacker to execute arbitrary code on the affected system, potentially compromising system integrity and confidentiality. The attack complexity is high, which may reduce the likelihood of exploitation. No known exploits are currently reported in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should monitor vendor communications for updates. No specific mitigations or workarounds are currently documented.