Microsoft Office Remote Code Execution Vulnerability

According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?
An attacker must send a user a malicious Office file and convince them to open it.

According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution?
The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the 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.

Security updates
https — https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates
16.0.5565.1001 — https://support.microsoft.com/help/5002897
16.0.5565.1000 — https://support.microsoft.com/help/5002791
16.0.5565.1000 — https://support.microsoft.com/help/5002795
16.0.5565.1000 — https://support.microsoft.com/help/5002900