Microsoft SharePoint Server Spoofing Vulnerability

There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?
Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order.

According to the CVSS metric, successful exploitation of this vulnerability could lead to loss of confidentiality (C:H)? What does that mean for this vulnerability?
Successful exploitation of this vulnerability allows an attacker to impersonate another user and access information based on the victim user's permission levels.

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.

Security updates
16.0.5565.1001 — https://support.microsoft.com/help/5002905
16.0.5565.1001 — https://support.microsoft.com/help/5002906
16.0.10417.20198 — https://support.microsoft.com/help/5002894
16.0.10417.20198 — https://support.microsoft.com/help/5002896
16.0.19725.20522 — https://support.microsoft.com/help/5002893