The ProfilePress WordPress plugin before 4.17.6 does not reject negative membership plan identifiers before checking whether a plan is active, allowing unauthenticated visitors to sign up for membership plans an administrator has deactivated and receive the role attached to them.

The ProfilePress WordPress plugin before 4.17.4 does not check that a membership plan is still active when checkout is used to change an existing subscription, allowing subscribers holding any subscription of their own to subscribe to plans the site owner has deactivated, including free plans that grant a user role.