A control device according to one embodiment of the present disclosure controls an update of a control program to be used to control a target device installed in a vehicle by an in-vehicle control device for controlling the target device. This control device is equipped with: a prediction unit for predicting a vehicle parking/stopping interval, and obtaining a first interval of time which is the predicted time; and an update control unit for controlling the processing that pertains to the control program update on the basis of the first interval of time.