Microsoft is force installing a Windows 10 update that removes the embedded 32-bit version of Adobe Flash Player from the operating system. The KB4577586 update marks an end to embedded Flash in the Windows 10, Windows 8, and Windows Server operating systems. Once installed, you cannot uninstall the update. In tests, the update is automatically installed without your permission and without prompting you first. BleepingComputer has contacted Microsoft to confirm if the update’s automatic installation is a mistake but has not heard back.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-force-installs-windows-10-update-to-remove-flash-player/