The fast technological development in smart cities is meant to increase humans’ conditions of life, but at the same time, it comes with various challenges and risks. People are already connected via gadgets and smartphones, while intelligent systems and appliances are utilized in many cities. Home devices, cars, and public venues are interconnected and communicate by sending data to each other, forming the Internet of Things. However, this opens new opportunities for malicious actors to launch different attacks that may have a destructive impact on the important infrastructures in a city. This paper proposes a framework for cybersecurity risk assessment in large-scale infrastructures alongside mitigation techniques and countermeasures. The methodology employed in the study is a qualitative one. It is based on 66 projects from the CORDIS database of the European Commission that are related to cybersecurity governance in smart cities. They are focused on research and innovation and held between 2022 and 2027. The work brings a significant contribution to the scientific community as it identifies the security risks in large-scale infrastructure and proposes mitigation techniques and countermeasures for these challenges.