I do not think any of the current computer systems can claim to be completely safe from a cyberattack.
As soon as a vehicle is connected and is able to communicate and exchange information with the road infrastructure, with other vehicles or with pedestrians, I believe there is a risk that the data will be intercepted and that unauthorized people will be able to control the vehicle remotely.
We have already had an example of that potential danger in the United States, two or three years ago, with a Jeep Cherokee.