Network Function Virtualization (NFV) and Software Defined Network (SDN) technologies are radically changing telecommunication networks. NFV virtualizes network services to reduce the dependency on underlying hardware which aids resource management, provides faster service enablement and lowers OPEX and CAPEX. SDN separates the control functions from the underlying physical network by decoupling the control and data planes thereby offering improved programmability, ease of deployment, management, reduced costs, better scalability, availability, flexibility and fine‐grain control of traffic. But how does this widespread adoption of NVF‐SDN impact on network security, especially with an increased attack surface implied by virtualization? In this workshop, we invite high‐quality submissions in the areas of NFV and SDN security and related areas. Submitted papers should highlight methods and approaches that can be used to analyse the security risks, requirements and techniques related to NFV and SDN and to provide methods and approaches to assure security and mitigate threats in NFV and SDN.