The extension's user detail view fails to verify that a requested user record matches the configured or logged-in target, allowing any visitor with access to the Detail or List plugin to retrieve another frontend user's profile data, including name, email, date of birth and address, by supplying an arbitrary user ID.

The extension fails to require the dedicated admin confirmation token when processing an admin-approval request, so a regular user confirmation hash, obtainable by any visitor through the public resend-confirmation action, is sufficient to self-approve a pending account awaiting admin approval.

The extension's invitation controller fails to stop processing after redirecting on invalid input (missing hash, non-existent, disabled, or deleted users), allowing an unauthenticated attacker to set a new password for and re-enable an arbitrary existing frontend user account. This vulnerability is only present in the 8.x versions of the extension.