On October 15, 2025, in line with its regular October Patch Tuesday schedule, Microsoft released the KB5066791 cumulative update for the Windows 10 operating system. This update elevated the system version to 19045.6456 (Version 22H2) and 19044.6456 (Version 21H2).

Serving as the last version upgrade for Windows 10 prior to the cessation of service support, this update tackled a substantial 172 security vulnerabilities. Among these, six were zero-day vulnerabilities that had already been publicly exploited.

The update encompasses a range of fixes and enhancements. It rectifies anomalies in the Chinese Input Method Editor, ensuring a smoother user experience for Chinese language input. It also addresses flaws in the USER32 Edit control, resolves timeout issues encountered in PowerShell Remoting, and introduces a Service Stack Update (SSU) to bolster system stability. Additionally, the problematic ltmdm64.sys driver has been removed.

Following this update, unless users opt to join the Extended Security Update (ESU) program, Windows 10 will cease to receive any further feature or security updates from Microsoft.