Today is the second Tuesday of October 2020 and the first batch of security updates or ‘B’ updates are now available for all supported versions of Windows 10. The patch is rolling out to PCs with May 2020 Update, November 2019 Update, May 2019 Update and later. To install the patch, head to the Settings app and click on the Windows Update option to install the patches. The first cumulative update for Windows 10, version 2004 is KB 4579311 and it comes with these fixes: Addresses an issue with a possible elevation of privilege in win32k.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-cumulative-updates-kb4579311-and-kb4577671-released/