CVE-2026-65789

Windows DNS is the “phone book” your network uses to translate names into IP addresses. This bug lets a remote attacker send special network messages to the DNS service, which can make the server crash or allow the attacker to run code as if they had local control. Think of it like someone finding a flaw in the book’s printing process: a bad page can cause the whole system to malfunction or hand control to the attacker.

This matters if your business runs Windows DNS Server on Windows 10 or Windows Server 2016/2019/2022/2025. The vulnerability is triggered remotely by sending crafted network packets, and it does not require authentication or user interaction. It is only a risk if the Windows DNS service is reachable from where an attacker can send network packets (for example, over the internet or any untrusted network path that can reach your DNS server).

This should be treated as urgent (RED) because attackers can potentially reach the DNS service over the network and cause remote code execution without needing a login. Even if you haven’t seen reports of this specific CVE being exploited yet, the flaw directly targets a core network service and has serious outcomes (takeover or outage).