A TikToker called el.chepito1985 explained the issue in some detail. Basically, the metal cover of the accelerator pedal isn’t attached well enough. Because of that, the piece can get wedged between the accelerator pedal and the bulkhead of the truck. If that happens, the pedal is pushed down all the way to the floor, causing the truck to accelerate at full speed. With a truck that weighs as much as the Cybertruck does and an acceleration time of a tick over 2.5 seconds to 60, this is a real issue. Luckily, you can override the issue by holding the brake down, but the second you let off, the car lurches forward.