Microsoft is rolling out a new cumulative update to devices with Windows 10 May 2019 Update (version 1903) and Windows 10 October 2018 Update with multiple fixes and improvements. The September 2019 cumulative update for Windows 10 includes security enhancements for Internet Explorer, Microsoft Edge, and input devices such as a mouse, keyboard, or stylus. The update is being rolled out via Windows Update, Microsoft Update, the Microsoft Update Catalog and Windows Server Update Services (WSUS for business) Microsoft is not aware of any known issues in both updates.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-kb4515384-and-kb4512578-released-with-fixes/