The User Registration & Membership WordPress plugin before 5.2.6 does not perform a capability check when saving its login settings, allowing authenticated users who have been granted a User Registration & Membership WordPress plugin before 5.2.6 management capability but not full administrator access to change arbitrary site options and escalate their privileges to administrator.
https://wpscan.com/vulnerability/609bbb7c-c19a-4c72-8cef-95598a2cfc0d/