While driving westbound on Lee Jackson Memorial Highway (U.S. Route 50) after passing the intersection with Stonecroft Boulevard in Chantilly, Virginia, the Autopilot system on my Tesla Model Y malfunctioned. Without any warning or obstacle in my lane, the vehicle suddenly and sharply veered to the right, directly toward two vehicles traveling in the adjacent lane. I was holding the steering wheel at the time and was able to immediately countersteer to prevent a collision. There were no audible or visual warnings from the vehicle before or during the incident. The Autopilot system did not display any messages or alerts, and no braking or turn signal was engaged by the system. The lane shift was abrupt and uncommanded. The dashcam footage clearly captured the incident, and it is available for inspection upon request. To my knowledge, the issue has not yet been reproduced or inspected by the manufacturer or service center. The vehicle has not been examined by police, insurance representatives, or others at this time. This unexpected maneuver created a serious safety risk for myself and nearby drivers.