The contact owns a 2018 Jeep Grand Cherokee. The contact had pulled up to the curve and placed the gear shifter in park(P). The contact exited the vehicle and walked to the rear of the vehicle to place his wife's luggage in the back. The vehicle rolled backwards, knocked the contact down, and the vehicle ran over the contact's legs. The vehicle came to a stop while the wheels were on top of the contact's legs. The contact's wife entered the vehicle and moved the vehicle off the contact. The contact's wife stated that the gear shift lever had moved independently. Unknown if any warning lights illuminated. The airport police responded. The contact was taken to the hospital by ambulance. The doctor diagnosed that the contact had sustained damage to the nerves, contusions, and a wound that the doctor was unable to close on his legs. The contact had road rash on his legs, back, and elbows. The contact's wife drove the vehicle to the hospital, and the vehicle functioned as intended. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The vehicle was parked at the residence. The contact related that failure to NHTSA Campaign Number: 24V838000 (SERVICE BRAKES, HYDRAULIC). The manufacturer was not made aware of the failure. The failure mileage was approximately 76,000.