For the latest information regarding the Meltdown and Spectre vulnerabilities see this document: A comprehensive guide to the Meltdown and Spectre vulnerabilities
Information
Microsoft released KB4058702 late the night of 1/3/18 (out of band) to address an Intel CPU firmware vulnerability. The patches released will be added to our patch definition update to be released later today, 1/4/18.
List of patches from Microsoft:
https://www.catalog.update.microsoft.com/Search.aspx?q=2018-01
Additional Information
Important information on detection logic for the Intel 'Meltdown' security vulnerability