Windows Push Notifications Elevation of Privilege Vulnerability

According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to win a race condition.

What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?
An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.

Security updates
10.0.17763.8644 — https://support.microsoft.com/help/5082123
10.0.20348.5020 — https://support.microsoft.com/help/5082142
10.0.19044.7184 — https://support.microsoft.com/help/5082200
10.0.26100.32690 — https://support.microsoft.com/help/5082063
10.0.26200.8246 — https://support.microsoft.com/help/5083769
10.0.22631.6936 — https://support.microsoft.com/help/5082052
10.0.25398.2274 — https://support.microsoft.com/help/5082060
10.0.28000.1836 — https://support.microsoft.com/help/5083768