CVE-2026-62820

Windows DNS Server is the service that translates names (like website addresses) into IP addresses so computers can find where to connect. This vulnerability is a timing bug: if an attacker sends the right network traffic at the right moment, they may be able to run their own code on the DNS server even without a login. If that happens, the attacker can often fully control the machine and tamper with files and data.

This matters if your business runs Windows DNS Server on Windows 10 or Windows Server 2016/2019/2022/2025. Because it is reachable in default configurations and needs no authentication or user interaction, systems exposed to untrusted networks are at higher risk. The core gate for exploitation is network reachability to the DNS server; no login is required, but the timing condition is described as high-complexity to successfully trigger.

This is RED urgency because it can allow remote attackers to gain complete control of a DNS server without authentication or user action. Even though successful triggering is described as high complexity, the issue is reachable in default configurations and the patch is available for all affected Windows versions, so you should act now.