Microsoft SharePoint Elevation of Privilege Vulnerability

What privileges could be gained by an attacker who successfully exploited the vulnerability?
An attacker who successfully exploited this vulnerability could gain the privileges of the compromised user.

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 metrics, successful exploitation of this vulnerability could lead to a high loss of confidentiality (C:H), and some loss of integrity (I:L) and no loss of availability (A:N). What does that mean for this vulnerability?
An attacker who successfully exploited this vulnerability could view sensitive information, a token in this scenario (Confidentiality), and make some changes to disclosed information (Integrity), but they would not be able to affect Availability.

Security updates
16.0.5478.1000 — https://support.microsoft.com/help/5002659
16.0.5478.1000 — https://support.microsoft.com/help/5002544
16.0.10416.20026 — https://support.microsoft.com/help/5002657
16.0.10416.20026 — https://support.microsoft.com/help/5002664
16.0.17928.20290 — https://support.microsoft.com/help/5002658