December has brought a few surprises in Windows PatchLand, but by and large, the coast is clear. “Clear,” that is, unless you made the mistake of installing the Win10 Fall Creators Update, version 1709 (or got pushed into it), before the nominal four-month testing period lapsed.
In broad terms, it’s safe to install this month’s Windows and Office patches, unless you’re using Win10 1709, although there are a few obscure gotchas that may bite you if you’re using Win7 with encrypted fileshares, or Active Directory app login. For those who installed Win10 1709 before letting the unpaid beta testers skate out on Crait, there’s very little reason to install this month’s security patches, as long as you don’t use Internet Explorer or Edge. Which, if the statistics are to be believed, you probably don’t.