Two days ago Microsoft released a final Windows 10 Insider Preview Build 18305 (19H1) for 2018 to Windows Insiders in the Fast ring. At the time Microsoft says it was the last major Insider build for the year, but that they may send out further Cumulative Updates as needed.
It seems those words were prophetic, as the company has just pushed out a Cumulative Update for the build, bringing the emergency patch for IE which is currently being exploited in the wild.
The flaw affects Windows 7 and 10 and Windows Server 2012, 2016 and 2019 versions of Explorer 11, Explorer 10 for Windows Server 2012 and Explorer 9 for Windows Server 2008. It is remotely exploitable via a malicious web page and provides the same access to the OS as the user being exploited.
If you are running a regular version of Windows 10 you can find the patches here. Otherwise, users can get the update by Checking for Updates in Settings or finding the download links at Microsoft here.