The contact owns a 2016 Hyundai Sonata. The contact stated that while driving at approximately 30 MPH and approaching a traffic light, the accelerator pedal was released, the vehicle sped up, the brake pedal was depressed, and the vehicle stopped. The contact stated the failure occurred after the vehicle was taken to the dealer for a software recall update. The contact stated that no warning lights were illuminated. The contact stated that the vehicle was taken back to the dealer where another update was completed. The contact stated that 4 days later the failure recurred as the accelerated pedal was released, the vehicle accelerated however when she attempted to depress the brake pedal and the vehicle sped up. The contact stated that she rear-ended another vehicle and stated that the driver-side air bag was deployed. The contact stated that medical attention was required for being hit in the chest by the air bag. The contact stated she was unaware if the occupants of the other vehicles needed medical attention. A police report was filed. The vehicle was taken to the dealer however a failure cause was not diagnosed. The manufacturer was made aware of the failure however, no assistance was offered. The approximate failure mileage was 20,000.