Yesterday, a post on Reddit unveiled a new cumulative update for Windows 10, called KB 3136562. There are download links in the reddit to valid x64 and x32 versions of KB 3136562, which point to Microsoft's official Windows Update download site.
Several intrepid Windows 10 build 1511 customers, attracted to a new cumulative update like a moth to the flame, decided to install the update and discovered that it bumps the Windows version (type
winver in the Cortana search box) to 10586.79.
There is no KB article posted for KB 3136562, and I've seen no reports of KB 3136562 being offered through Windows 10's forced updates.
As best I can tell, the last official cumulative update for build 1511 was on Jan. 27. It's KB 3124262, cumulative update 8, version 10586.71.
My advice: Don't touch KB 3136562. Although this is the first time I've seen a Windows 10 update posted prematurely to the download.windows.update.com site, that kind of screw-up has happened with Windows 7, in particular.
The two release actions are independent of each other: Just because there are bits on windows.update.com doesn't mean the update is ready.
If you install this unannounced KB 3136562, there's no telling if the real Cumulative Update 9 will install over the top of it, or if you'll be stuck trying to back out this one.