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.

Mautic Sessions could be hijacked due to tracking contacts by an auto-incremented ID