Vehicles are currently getting more and more digitalized and the number of interfaces exposed to the internet and other digital equipment are increasing. This is especially true for heavy vehicles, where different third party add-ons adds to the interfaces connecting to the rest of the world. At the same time a large part of the heavy vehicle fleet performs vital societal functions. MSB therefore has initiated a study of cyber security in heavy vehicles, focused on vehicles used in the civil defence operation of Sweden, to illuminate the current status and future trends within the area. The study is part of the NCS3 collaboration and is conducted as a literature survey within the area, together with interviews with personnel having different roles within the civil protection services and vehicle manufacturing. The result shows that the cyber security work still is in its infancy, but that the manufacturing parties have started to adopt cyber security principles when developing new vehicles. In spite of the fact that the cyber security level is low at the same time as the attack surfaces are increasing the traditional focus on reliability and safety partially decreases the risk of successful attacks. Currently we estimate some sort of Denial-of-Service attack to pose the biggest threat.