Unknown system that failed but vehicle equiped with EyeSight and all of Subaru safety features. Air bag did not deploy. Pulling into curbed parking space at city park. Speed <10 mph while in parking lot. Applied brake while pulling in space to park and car accelerated jumping the curb. The car was out of control and luckily heading into the woods. Tried to apply brake again but car kept accelerating. Car went approximately 10-12 feet and crashed into a tree. I suffered only stiffness and sore muscles from the seatbelt. An accident report was filed with local police department. No warning lamps, messages or other messages appeared prior to the incident.