This is according to a group of UC Santa Barbara researchers who stumbled across the exploit (via Engadget) that could let a complete stranger/hack track your driving in real-time, even if you did not mean to share your trip details with them. This is done by reverse-engineering Waze’s server code that creates thousands of ghost drivers that monitors drivers around them, kind of like how when you are driving you can see other Waze users who are near you.
In fact this exploit even allows them to manipulate it so that they can fake traffic jams, which in turn could force the app to redirect the driver to somewhere else the hacker might have in mind. According to the researchers, they claim to have been in touch with Waze who said that they have tackled some of the issues, but subsequent tests by the researchers have found that Waze’s solutions weren’t that effective.
That being said, Waze is still working on trying to close this exploit and so far we haven’t really heard reports of people being stalked via Waze due to this exploit, so for now we guess you are safe, but maybe if you want to be extra safe then you could consider enabling invisible mode while you use the app.