Windows promptly released security updates for all the Windows 10 builds in ordered to fix the Meltdown and Spectre vulnerabilities discovered by the Google Project Zero team earlier this week. Although there have not been reports of exploited systems, Window 10 users had better install the patch.
https://www.notebookcheck.net/Microsoft-releases-emergency-patches-to-address-Meltdown-and-Spectre-vulnerabilities-affecting-most-current-processors.276794.0.html