Microsoft Outlook Elevation of Privilege Vulnerability

According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of confidentiality (C:H) and major loss of integrity (I:H) but have no effect on availability (A:N). What does that mean for this vulnerability?
Exploiting this vulnerability could allow an attacker to disclose files and modify data, but the attacker cannot impact the availability of the files.

What privileges could be gained by an attacker who successfully exploited the vulnerability?
The attacker would gain the rights of the user that is running the affected application.

Security updates
https — https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates