How are security updates handled on a VPS?

There are two different types of security updates.

Application Security Updates

Because any application can be installed on a VPS, on unmanaged VPSes, you are responsible for ensuring application security is maintained by applying updates from vendors when necessary.

OS Security Updates

On unmanaged VPSes, linux kernels and modules are managed for all VPS environments, but all Linux OS files within your VPS remain your responsibility.