5G aims to provide faster speeds, very low latency, and higher reliability, reliability, and availability. The 5G Core network based on a service-based architecture includes a containerized network function. In order for such a containerized network function to be used in a network system, it must be secure from security threats while ensuring Quality of Service in network services using a container, but many studies have demonstrated that Denial-of-Service, privilege Escalation, and Container Escape attacks are possible in a container environment through incorrect environmental configuration, vulnerabilities in resource isolation technology, or bypass technology. This means that such an attack can be valid in a network environment in which containers are deployed, and if an attack is successful, it can cause serious damage the entire 5G network. Therefore, this paper introduces the Container security threat and points out that it may be valid for containerized network functions in 5G Core, and we intend to conduct research that can mitigate these security threats in the future.