The updates address vulnerabilities in Microsoft Windows, Microsoft Edge, Microsoft Office, Microsoft Office Services and Web Appsand Adobe Flash Player for Windows 8.1 and above. Addressed in the updates are Remote Code Execution, Elevation of Privilege and Denial of Service.
Information about the update for Windows 10 is available at Windows 10 update history
Reminder: Today marks the last time Microsoft will release bulletins. Starting in February, the information will only be available from the new Security Updates Guide which includes the ability to view and search security vulnerability information in a single online database. The guide is described as a "portal" by the MSRC Team in Furthering our commitment to security updates.
TechNet: Microsoft Security Bulletin for January 2017
Windows Update Changes: More on Windows 7 and Windows 8.1 servicing changes – Windows for IT Pros