network – Is it possible to access a roaming virtual machine from outside the host operating system?

I would like to know if it is possible to access one way or another to a guest operating system wandering from the outside of the system. Host exploitation.

I use vagrant / virtualbox only for local development and so I did not think much about security. For example, I allowed nginx on a firewall via sudo ufw allows "Nginx HTTP". I have redis and mongo listening on ip with their default ports transferred between host and guest systems, and no security-related configuration.

The host and guest systems are connected via a private network via "private_net", ip: "" I therefore assumed that everything was fine because the guest OS should only be accessible from the host OS.

But I would like to know if that is really well and I will do it well?