A communication device includes: a communication section that transmits and receives a message in a network; an acquisition unit that acquires state information on a state of an object for which the network is provided; an estimation unit that estimates the state of the object based on the state information acquired in the acquisition unit; a setting unit that sets a filtering rule based on the state estimated in the estimation unit; and a filter unit that executes filtering processing for the message in accordance with the filtering rule set in the setting unit.