# Steam API data leak of unreleased video games > Live situation record from CLSTR: https://clstr.news/situations/steam-api-data-leak-of-unreleased-video-games > Updated: 2026-09-09T02:34:30.000Z. Sources: 44. Developments: 2. A technical error following a maintenance window at Valve caused a major Steam API data leak, exposing achievement lists for numerous unreleased and unannounced video games. The leak allowed third-party tracking sites to index private data, revealing details for titles such as Kingdom Hearts IV, Mega Man: Dual Override, and Gears of War: E-Day. Specific details regarding Persona 6 emerged from the leak, suggesting the game may feature a crime-investigation theme set in Yokohama. Leaked achievement descriptions point to gameplay mechanics including investigation meetings, a notebook for tracking leads, and a Persona fusion system. The data also mentions potential locations such as Justiceopolis and Unmasked Yokohama, alongside an organization called Hex. While Atlus and Sega have not officially confirmed these specific leaked details, previous listings indicated a 2027 release window for the title. ## Timeline ### 2026-09-09: Persona 6 gameplay and setting details leaked via Steam achievements Leaked Steam achievements on Exophase suggest Persona 6 will feature a crime-investigation theme set in Yokohama, involving a group called Hex and new combat and social mechanics. 6 sources. https://clstr.news/cluster/persona-6-gameplay-and-setting-details-leaked-via-steam-achievements ### 2026-09-09: Steam API leak reveals details for Persona 6 and Kingdom Hearts IV A Steam API error leaked achievement data for dozens of unreleased games, revealing potential story details for Persona 6 and new worlds for Kingdom Hearts IV, including a possible Star Wars setting. 41 sources. https://clstr.news/cluster/persona-4-revival-details-revealed-by-atlus-at-pax-west --- Cite as: Steam API data leak of unreleased video games. CLSTR, https://clstr.news/situations/steam-api-data-leak-of-unreleased-video-games