Hackers have reportedly stolen the source code to FIFA 21 and game engine Frostbite.
Vice reported the hackers claimed to have obtained 780GB of data and had put it up for sale.
EA confirmed the breach in a statement that also insisted no player data had been stolen.
"We are investigating a recent incident of intrusion into our network where a limited amount of game source code and related tools were stolen," an EA spokesperson told Motherboard.
"No player data was accessed, and we have no reason to believe there is any risk to player privacy. Following the incident, we've already made security improvements and do not expect an impact on our games or our business. We are actively working with law enforcement officials and other experts as part of this ongoing criminal investigation."
The incident is the latest in a string of high-profile video game hacks. In November, Capcom suffered a devastating hack that revealed personal information of up to 350,000 people, as well as the company's upcoming release slate.
And in February, CD Projekt suffered a ransomware attack that reportedly involved the source code to Cyberpunk 2077 and The Witcher 3. Last night, during the Summer Game Fest show, CD Projekt issued a statement warning employee data may have been stolen, too.