Hybrid threats to critical infrastructure represent a multifaceted challenge that requires a coordinated and comprehensive approach to mitigate. By addressing the vulnerabilities and implementing robust security measures, nations can enhance the resilience of their critical infrastructure against these evolving threats. The work reported here stems from collective discussions and inputs from a working group on Critical Infrastructure: Hybrid threats, risk assessments, and vulnerabilities. The working group focused on identifying the scope of threats, risks, and vulnerabilities to develop a comprehensive solution toolkit for cross-sectoral applications. Based on the recommendations of the working group, we believe that the solutions and best practices can be widely applied across the spectrum of threats and vulnerabilities. This report focuses on an overview of hybrid threats and how several solution pathways encompassing technical, social, and policies can be applied to bridge vulnerabilities.