mettle sendportal Invitation WorkspaceInvitationsController.php destroy authorization

A weakness has been identified in mettle sendportal up to 3.0.1. Affected is the function destroy of the file app/Http/Controllers/Workspaces/WorkspaceInvitationsController.php of the component Invitation Handler. This manipulation of the argument invitation causes authorization bypass. The attack may be initiated remotely. The project was informed of the problem early through an issue report but has not responded yet.