There’s a different impact for different vulnerabilities.

Security Rating Definitions

Like I said, there are four different ratings in this system.

They’re all listed below with explanations as Microsoft defines them.

Microsoft recommends applying Critical updates as soon as possible.

Microsoft only recommends that users consider applying Moderate updates.

you could read more about Microsoft’s rating system at theMicrosoft Security Response Center Security Update Severity Rating Systempage.

Each one has at least one Knowledge Base Article that helps explain more information about the update.

you’re free to go through the security bulletins at theSecurity Advisories and Bulletinspage on Microsoft’s website.

it’s possible for you to get notifications when Microsoft releases new bulletins.

The explanations from above are describing the worst possible outcome.

Security advisories are just another way for Microsoft to relay security information to users.