UsersWP - Social Login < 1.5.10 - Unauthenticated Account Takeover via Unverified Provider Email

The UsersWP WordPress plugin before 1.5.10 does not verify that a social login provider has confirmed ownership of an email address before using it to resolve an existing account, allowing unauthenticated attackers to log in as any user, including administrators, whose email address they can assert through a provider account of their own.