Honestly, I don't think so because an Iphone 8 is still being backed up with the newest updates.. but maybe if you are not on the recent update you MAY be able to jailbreak it, I think.
Yes it can be jailbroken. You will need to make or download custom firmware and load it to the phone with "recovery" mode with a special software. I've been doing it for customers since iPhone 4 don't matter what version iOS is on it.
