The stolen data allegedly includes information about upcoming projects, ad campaigns, company logins, and more.
Disney is investigating this matter," a company spokesperson said in a brief statement.
Nullbulge, the hacker group, claims to have published thousands of messages from Disney's internal Slack channels.
The data reportedly spans "10,000 channels, every message and file possible," including unreleased projects and internal links.
Leaked details include a sequel to Aliens Fireteam Elite and a Fortnite x Disney collaboration.
Nullbulge states its mission is to protect artists' rights and ensure fair compensation, targeting Disney for its handling of artist contracts and AI.
If confirmed, Disney joins other major companies like Insomniac Games and Rockstar, who faced significant cyberattacks last year.
While film and television have been less targeted, notable hacks include Sony Pictures in 2014 and recent attacks on Roku, Ticketmaster, and AT&T.