Microsoft Office SharePoint Elevation of Privilege Vulnerability

Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.

I am running SharePoint Server 2016. Do the updates for SharePoint Enterprise Server 2016 also apply to the version I am running?
Yes. The same KB number applies to both SharePoint Server 2016 and SharePoint Enterprise Server 2016. Customers running either version should install the security update to be protected from this vulnerability.

What privileges could be gained by an attacker who successfully exploited this vulnerability?
Successful exploitation could allow an attacker to run script in the security context of the affected SharePoint user and perform actions permitted to that user.

How could an attacker exploit this vulnerability?
An authenticated attacker with permissions to add or modify content on an affected SharePoint page could store malicious script content in the page. The script could run in the security context of another user when that user views and interacts with the affected content, potentially allowing the attacker to access or modify SharePoint data available to that user.

Security updates
16.0.20326.20190 — https://support.microsoft.com/help/5002927