A large-scale Steam achievement leak has exposed data tied to dozens of unreleased games, including Persona 6, Kingdom Hearts 4 and multiple projects that have not been officially announced. The information appears to have become publicly accessible through Steam’s API before being automatically collected by third-party achievement trackers including Exophase. The resulting data includes achievement names and descriptions that potentially reveal story details, locations, mechanics and the existence of previously unknown games.
Exophase owner Mike Bendel, known online as x3sphere, said games with achievements that should have remained private were suddenly accessible through Steam’s API, allowing the site’s automated systems to scan them. That explanation is supported by individual Steam API endpoints circulated during the leak, as well as achievement listings appearing across tracking services. There is currently no indication that publishers themselves deliberately released the information, and Valve has not publicly explained what caused the private data to become accessible.
The scale of the exposure quickly became apparent as more listings were discovered. Reported games include Persona 6, Persona 4 Revival, Kingdom Hearts 4, Fable, Gears of War: E-Day, Judas, Control Resonant, Ace Combat 8, Silent Hill: Townfall and Minecraft Dungeons 2, alongside apparent entries for Dragon Ball Xenoverse 3, Attack on Titan 3 and other projects that had not been announced at the time the data surfaced. Some listings may ultimately require further verification, particularly where an app ID or achievement set cannot yet be confidently connected to a publicly known project.
The most sensitive material involves games whose developers have revealed relatively little about their stories. Persona 6’s surfaced achievement list contains progression and narrative references that go considerably beyond what Atlus has publicly shown, while Kingdom Hearts 4 achievements reportedly expose locations and other potential story details. Square Enix recently confirmed that Kingdom Hearts 4 remains scheduled for late 2027, meaning these achievements have appeared more than a year before the game’s planned release.
The leak is also notable because achievement data can reveal far more than whether a PC version of a game exists. Achievement names and descriptions are often tied to bosses, chapters, endings, characters, collectibles and major gameplay milestones, making a complete list particularly damaging for story-heavy games. Even announced titles can therefore have significant unrevealed content exposed without any game files, screenshots or development builds being obtained.
More importantly, apparent achievement sets attached to unannounced games could effectively disclose projects before publishers are ready to reveal them. That makes the incident comparable in effect to other backend database leaks, where information unintentionally made accessible by a platform provides evidence of games or releases that have not been formally announced. However, names appearing in backend data should still be treated cautiously until the relevant publisher confirms them, since development projects can change names, be cancelled or represent internal testing rather than finished products.
The achievement lists spread rapidly across social media and gaming communities after being indexed, making the information difficult to contain even if Steam has since restricted the underlying API access. Players trying to avoid spoilers for Persona 6, Kingdom Hearts 4 and other upcoming releases may therefore encounter details copied from the leaked listings well beyond the original tracking pages. For publishers, the more significant issue is that a platform-level visibility problem appears to have exposed information from numerous unrelated games at once rather than a leak originating from a single studio.
