Abstract—For increased safety and fuel-efficiency, vehicle pla- toons use Cooperative Adaptive Cruise Control (CACC) where vehicles adapt their state, incl. speed and position, based on information exchanged between vehicles. Intruders, however, may carry out attacks against CACC platoons by exploiting the communication channels used to cause harm, e.g., a vehicle crash. Therefore, during design-phase, engineers should provide evidence supporting platoon security. This paper proposes a formal framework for the security verification of CACC platoons to provide such evidence based on precise mathematical models. Our vehicle platoon models support the specification of both cyber, e.g., communication protocols, and physical, e.g., speeds, position, vehicle behaviors. Moreover, we propose intruder mod- els that are parametric on his capabilities of manipulating com- munication channels, i.e., message injection and blocking. Our model is implemented enabling the automated formal verification involving both platoon and intruder models. We validate our machinery with a number of attacks taken from the literature and novel attacks discovered by using our formal machinery.