Microsoft has had a slightly rough time with updates lately, with some updates not working properly in August and others working far too well in September. The latest patch is almost certainly a formal fix for the IE zero-day vulnerability that made the news half way through September. Microsofts Advance Notifications dont actually detail exactly what is going to be fixed, so we cant be sure that CVE-2013-3893 is being patched for good, but given the seriousness with which Microsoft handled its appearance in the wild, it is a good guess.”]