ABSTRACTThe forthcoming 5G operational environment entails heterogeneous and multi-dimensional ecosystems where cyber assets, digital actors and cyber-physical risks coexist. In this context, theprediction and anticipation of the attacks propagation thorough thetargeted systems promises to be some of the major workhorses ofthe emerging self-protection capabilities. In the grounds of the SelfOrganizing Network (SON) paradigm, it is expected that by takinginto account proactive actuations, the decision and enforcement ofthe best courses of action will be enhanced. With the aim on contributing to their planning and execution, this paper introduces anovel framework for proactive self-protection on 5G environments,the description of an architectural framework able to sustain therest of the anticipation enablers, the formalization of a knowledgerepresentation and reasoning strategy for active cyber threat mitigation, and a prediction strategy adapted to the difficulties inherentin analyzing events on 5G scenarios. The effectiveness of the proposal has been demonstrated by proof-of-concept instantiation foranticipating the impact of Denial of Service (DoS) attacks on a realcommunication environment.