Along with all the announcements Microsoft made during the October 2016 Microsoft Event, the Redmond giant today released Windows 10 PC build 14393.351 for Insiders on the Slow and Release Preview rings. If you have joined one of these rings, the update will arrive on your PC very soon.
The update got ID KB3197954. The appropriate support page in Microsoft Knowledge Base is not available yet.
Since it is a cumulative update, it should bring performance and security fixes which will reach the stable channel of Windows 10 after a short period of time.
If you are a Windows Insider of the Slow or Release Preview ring, go to Settings - Update & security - WIndows Update and click Check for updates there. Credits: Neowin.
Update: according to Neowin, the update will reach the Release Preview ring only.