Kanboard is project management software focused on Kanban methodology. Prior to 1.2.51, Kanboard's user invite registration endpoint ("UserInviteController::register()") accepts all POST parameters and passes them to "UserModel::create()" without filtering out the "role" field. An attacker who receives an invite link can inject "role=app-admin" in the registration form to create an administrator account. Version 1.2.51 fixes the issue.