Last week Microsoft said they wouldn’t be releasing a new Windows 10 Insider build until the New Year but they have pushed out an update to the current insider build today. For Windows Insiders running Windows 10 Creators Update build 14986 there is a cumulative update that looks like it contains a security update for the OS:
Cumulative Update for Windows 10 Version Next (14986) (KB3206309)
A security issue has been identified in a Microsoft software product that could affect your system. You can help protect your system by installing this update from Microsoft. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article. After you install this update, you may have to restart your system.
The update requires a reboot after installing.