Normally, Microsoft releases updates for Flash in Edge and Internet Explorer along with everything else on the second Tuesday of each month.
This month, something went wrong with the Windows Update system, and Microsoft pushed all the February updates to March, including an expected fix for a serious SMS flaw.
Someone at Microsoft apparently realized that this decision would leave some Flash users (those using Flash in Edge and Internet Explorer) vulnerable for an extra month. Flash vulnerabilities are targeted aggressively by malicious hackers, so this is obviously a bad thing. As a result, Microsoft has released a Flash update, one week later than originally planned.
Anyone who uses Flash in Internet Explorer or Edge should visit Windows Update and install the Flash update as soon as possible.
So we do get a Microsoft Security Bulletin Summary for February 2017 after all, but it only includes a single bulletin.