CVE-2026-16736

The User Registration & Membership WordPress plugin before 5.2.8 does not verify that the visitor requesting its membership confirmation page owns the account named in the request, nor that any registration or purchase has taken place, allowing unauthenticated users to retrieve another user's email address, profile fields, role and membership order details. Exploitation requires the site owner to have added a user smart tag to that page's configurable message, which the shipped default does not contain.

The User Registration & Membership WordPress plugin before 5.2.8 does not check the capability of the user making a membership purchase, and does not validate the payment method or the plan submitted with it. Any authenticated user such as a subscriber can be granted the WordPress role attached to a paid plan without paying for it.

The User Registration & Membership WordPress plugin before 5.2.8 does not properly restrict who may author a membership plan or validate the plan a user attaches to their own account. Authenticated users with Author-level access and above can assign themselves an arbitrary role and escalate their privileges to Administrator.

The User Registration & Membership WordPress plugin before version 5.2.6 does not perform a capability check when saving its login settings. Authenticated users with plugin management capability but without full administrator access can change arbitrary site options and escalate their privileges to administrator.

The User Registration & Membership WordPress plugin before version 5.2.5 does not verify that the account whose pending email change is being cancelled belongs to the user making the request. Authenticated users with Subscriber-level access and above can cancel any other user's in-progress email change, including an administrator's.