On August 31, 2026, at approximately 11:07 a.m., the vehicle had been parked and was stationary with the engine running. After remaining stationary for a short period of time, the vehicle suddenly and unexpectedly moved backward rapidly on its own. I did not intentionally command the vehicle to move backward and I did not press the accelerator. While the vehicle was moving backward, I pressed the brake pedal twice in an attempt to stop the vehicle. The brake pedal felt soft, as though there was little or no braking resistance, and the vehicle did not respond to my braking attempts. Immediately afterward, the vehicle unexpectedly moved forward and struck a vehicle in front of it. That vehicle was then pushed into another vehicle. The cause of this incident is currently unknown. I am concerned about a possible braking-system failure, unintended vehicle movement, powertrain/transmission control malfunction, electrical/electronic control malfunction, or other vehicle-control defect. The vehicle is available for inspection. I have requested that the dealer preserve all electronic and diagnostic data before any repair, reset, software update, or reprogramming is performed.