  5G is enabling different services over the same physical infrastructure
through the concepts and technologies of virtualization, softwarization,
slicing and cloud computing. Virtual Mobile Networks (VMNs), using these
concepts, provide an opportunity to share the same physical infrastructure
among multiple operators. Each VMN Operator (VMNO) can have own distinct
operating and support systems. However, the technologies used to enable VMNs
have their own explicit security challenges and solutions. The integrated
environment built upon virtualization, softwarization, and cloudification,
thus, will have complex security requirements and implications. In this vain,
this article provides an overview of the security challenges and potential
solutions for VMNs.
