2012 Lexus Is

While stopped at a stop light vehicle RPM went very high. It reached the red zone. Vehicle started moving forward (while still on Drive and the brake pedal fully pressed). I immediately put the vehicle in Park. RPM continued to remain high. I removed my foot off the brake when the vehicle was in park. I turned the engine off, waited couple of seconds and turned it back on. At that point everything worked normally. Outside temperature was about 38 deg F. Car was not fully warmed up at the time. Floor mat had nothing to do with this incident. After restarting the engine it is working fine without any adjustment to the floor mat. Incident could have resulted in major crash or injury. Luckily it happened when the vehicle was stopped at at red light. Putting the car in PARK and turning off the engine resolved the issue. This is a serious issue on 2012 IS250. Check engine light is not on. Vehicle will be taken to the Lexus dealer for checking. If the car was in drive, this kind of revving up of the engine would have caused serious accident. Also, if I had not put the car in Park, it would have overcome the braking power and pushed the car to the intersection at red light. Engine RPM went way too high (in the red zone). This is the first incident. This 2012 Lexus IS250 has 69364 miles.