Of course it is, if you rely on that boundary. The 'consumer' use of tailscale is just as a reverse proxy, and that's how I figured GGP sees it. I don't have anyone on my tailnet, and when I did they didn't have ssh keys, and if they did I imagine there'd be many paths to privilege escalation, certainly it's a bigger surface than sshd. So I was clarifying it seems like an escalation from authorized execution to privileged execution, and not e.g. from unauthorized users to RCE

Privilege escalation is nothing to worry about on root accounts

I guess if you have an industrial arm connected then they could escalate to physical access

The "root account" is your assumption now no?