Steam achievement lists for unreleased games including Persona 6, Persona 4 Revival, and Kingdom Hearts IV were accidentally exposed through Valve's API and indexed by achievement tracking site Exophase. The leak revealed dozens of unannounced titles across multiple publishers.
A Steam API vulnerability allowed achievement tracking site Exophase to scrape unreleased achievements for hundreds of unannounced games, including Kingdom Hearts 4 and Persona 6, exposing major spoilers and unconfirmed titles. Exophase's owner confirmed the leak resulted from a mistake on Valve's end that lifted access restrictions. This marks the second significant security incident for Valve in two weeks.