An issue was discovered in Mautic 1.x and 2.x before 2.13.0. It is possible to systematically emulate tracking cookies per contact due to tracking the contact by their auto-incremented ID. Thus, a third party can manipulate the cookie value with +1 to systematically assume being tracked as each contact in Mautic. It is then possible to retrieve information about the contact through forms that have progressive profiling enabled.