Microsoft’s January 2026 Patch Tuesday fixes 112 CVEs, including an exploited Windows DWM zero-day, plus critical flaws across SharePoint, Office, and Windows services.

Windows 11 January 2026 Update is rolling out for Windows 11 25H2, 24H2, and 23H2, as well as Windows Server 2025 and 2023.

Microsoft today issued patches to plug at least 113 security holes in its various Windows operating systems and supported software. Eight of the vulnerabilities earned Microsoft’s most-dire “critical” rating, and the company warns that attackers are already exploiting one of the bugs fixed today.

Microsoft's January security updates for Windows 11 also appear to be disrupting Outlook. Microsoft is investigating problems with POP mail accounts.

Reinstalling Windows is disruptive. Run these built-in Command Prompt repairs in the right order to fix disk, system files, and update issues first.