A decade's worth of Steam files totaling more than 12TB has leaked

Steam A treasure trove of Steam data has been leaked, which seemingly contains everything that was published on Steam between 2003 and 2013. The leak totals more than 12TB in scale and includes beta builds and completely finished games from Valve's own franchises, including Half-Life, Left 4 Dead and Portal. A GitHub catalog has compiled most of the titles, which also includes games from major franchises like Call of Duty, Fallout and Civilization, as well as those from indie developers. Someone leaked 12 TB of Valve's internal builds and game assets from 2003 to 2013. This includes early versions of Portal 2, Left 4 Dead, CS:GO, F-Stop and potentially EP3. The community is still researching everything, so the next few days might be insane... There's a Weaponizer... pic.twitter.com/Sg7OqJjL2X — ‎Gabe Follower (@gabefollower) August 29, 2026 The sheer size of the leak means people are still combing through the details, but so far internet sleuths have uncovered details of the unreleased F-Stop game from Valve that features gameplay revolving around a camera that can manipulate real world objects. Of course there are hints of the long-rumored conclusion of the Half-Life franchise in the leak, but it references Half-Life 2: Episode 3, which was supposed to be the final game in the series but was later canceled. There are plenty of social media posts circulating about this Steam leak, but Valve hasn't commented on this yet so we should take all this info with a grain of salt. Te zombie, który znalazł się w plikach Portal'a świadczy o wczesnej wersji FStop. Tutaj jest stworzony już do tego przykładowy model wraz z animacjami. Czym tak naprawdę jest FStop? To gra, którs miała być prequelem do Portal. Gra przeszła transformację jako sequel. pic.twitter.com/eeC1B66XWq — Paplock (@PAPL0CK) August 30, 2026 According to X user Gabe Follower, the leak was made possible thanks to a publicly accessible endpoint. The X user explained that's why we only see files dating up to 2013, since that's when Valve switched over to another storage system. We reached out to Valve for comment about this and will update the story when we hear back.