It's the second week of the month and that means it's Patch Tuesday time, the monthly delivery of fixes for Microsoft's quiver of software arrows. This month, they have targeted a bunch of issues rated as "critical".
A total of 46 vulnerabilities have been fixed according to this month's advisory.
Given we know what happens to unpatched systems (cough... WannaCry...cough...NotPetya) it's highly recommended you patch systems as soon as possible or take steps to isolate vulnerable systems.
Most IT admins should be ready for this but not everyone has the luxury of an IT departments or a managed service provider to look after this. If you're responsible for patching systems, then it's time to schedule some time to apply these patches.