Then you need to run things with as least privilege as possible. Sadly, Docker and containers in general are an anti-pattern here because they’re about convenience first, security second. So the OP should have run the contains as read-only with tight resource limits and ideally IP restrictions on access if it’s not a public service.
Another thing you can do is use Tailscale, or something like it, to keep things being a zero trust, encrypted, access model. Not suitable for public services of course.
And a whole host of other things.