Did Steam just leak Persona 6 and Kingdom Hearts 4? Dozens of unreleased and unannounced games had achievement lists exposed through its API

Steam appears to have accidentally opened a door it really should have kept shut. In the early hours of September 9, achievement lists for dozens of unreleased and, in some cases, completely unannounced games suddenly became visible through Steam’s API and were quickly picked up by tracking sites such as Exophase and SteamDB.


The result was an unusually messy leak containing everything from minor gameplay details to potential story spoilers for some of gaming’s biggest upcoming titles. Persona 6, Kingdom Hearts 4, Fable, Dragon Ball Xenoverse 3 and Ace Combat 8 were among the games caught in the fallout, with the list continuing to grow.

This was not a conventional hack where someone broke into a publisher’s servers and dumped confidential files online. The information appears to have become accessible because of a problem involving Steam’s API, after which automated tracking services did exactly what they are built to do: scan Steam data and add newly visible information to their databases.

Mike Bendel, the owner of Exophase, said the situation looked like “a possible screw up on Valve’s end.” He explained that games whose achievements were supposed to be private had suddenly become accessible through the API, which allowed Exophase to scan them. He also pointed out that seeing unnamed games with visible achievements was highly unusual.


That distinction matters because the leak spread incredibly quickly. Once achievement information was readable by automated systems, it did not really matter that the games themselves were still unreleased. Tracking sites indexed the information, screenshots and lists started circulating, and gaming communities began connecting the dots almost immediately.

Persona 6 was arguably the most eye catching name in the entire mess. Atlus has revealed very little about the game and has not even announced a release window, yet its reported Steam achievement list contains 48 achievements with references to its setting, characters, systems and story progression.

The biggest apparent reveal is Yokohama, which is repeatedly referenced in the achievements. The list also mentions an organisation called Hex, investigations, romance, Connections and locations including Hellrite Stage, Justiceopolis and Reverie Dreamland. Some achievements also appear to reference new combat and investigation mechanics.

And yes, fans immediately started digging even deeper. One Persona 6 Reddit user claimed the internal achievement data may even point towards the protagonist’s Persona, although that remains fan interpretation rather than an official confirmation. The reaction has been predictable: some fans are fascinated, while others are desperately trying to avoid anything that might spoil the game.


Kingdom Hearts 4 may have an even more painful problem for spoiler conscious fans. Its leaked achievements reportedly contain references to multiple worlds and story elements that have not been formally revealed, with clues pointing towards locations and Disney properties. One achievement referencing a “Galaxy Far, Far Away” has reignited speculation that Star Wars could feature in the game.

The leak is particularly awkward for a series like Kingdom Hearts, where discovering a new Disney world is often part of the fun. One Reddit discussion summed up the mood rather perfectly, with a user joking that fans went from knowing very little about the game to suddenly having “nearly all the worlds.”

The strange part is just how many games were apparently caught up in the same incident. Reports and community tracking have included Persona 4 Revival, Dragon Ball Xenoverse 3, Gears of War: E-Day, Fable, Control Resonant, Judas, Metro 2039, Tomb Raider: Legacy of Atlantis, Minecraft Dungeons 2, Ace Combat 8 and several other upcoming projects. Some unannounced games have also reportedly appeared in the data.

For some games, the information is barely useful. For others, it can reveal bosses, locations, story beats, characters or gameplay systems well before developers are ready to talk about them. The achievement lists can also be works in progress, meaning developers could still change or remove content before launch.


That is why the leak does not necessarily mean every apparent detail is locked in. But the sheer amount of information appearing at once is what makes this incident unusual. One Reddit user described it as a combination of a Steam backend permissions problem and automated bots constantly scanning exposed data.

The reaction has moved between disbelief, excitement and genuine frustration. “We knew almost nothing about Persona 6. All achievements,” one user wrote in a Reddit discussion, before pointing out that the leak had also exposed huge amounts of information about Kingdom Hearts 4 and even games that had not been announced.

Another player urged people to be careful with gaming communities because the spoilers were spreading rapidly. That may end up being the biggest headache from the incident. Even if Valve fixes the original API problem, screenshots and copied achievement lists can continue travelling across Reddit, X, Discord and gaming forums long after the original pages disappear.

For now, the safest assumption is that upcoming games with Steam achievement data may contain spoilers that developers never intended players to see this early. And for anyone waiting on Persona 6 or Kingdom Hearts 4, perhaps the smartest move is also the simplest one: stop searching for the achievement lists.