Paint 3D Remote Code Execution Vulnerability

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.
For example, when the score indicates that the Attack Vector is Local and User Interaction is Required, this could describe an exploit in which an attacker, through social engineering, convinces a victim to download and open a specially crafted file from a website which leads to a local attack on their computer.

How do I get the updated app?
The Microsoft Store will automatically update affected customers. Alternatively, customers can get the update immediately; see here for details.
It is possible for customers to disable automatic updates for the Microsoft Store. The Microsoft Store will not automatically install this update for those customers.
Customers using the Microsoft Store for Business and Microsoft Store for Education can get this update through their organizations.
App package versions 6.2305.16087.0 and later contain this update.
You can check the package version in PowerShell:
Get-AppxPackage -Name Microsoft.MSPaint

Security updates
6.2305.16087.0 — https://www.microsoft.com/en-us/p/paint-3d/9nblggh5fv99#activetab=pivot:overviewtab