Report: 13TB of Steam data leaked after users access 'publicly accessible

Bryant Francis,Senior Editor,GameDeveloper.com

August 31, 2026

2 Min ReadImage by Rokas via Adobe Stock

Steam platform owner and Counter-Strike: Global Offensive developer Valve appears to have suffered an unusual breach sometime last week. As reported by Kotaku, the leak—dubbed "the Steam2 leak" by users on X—contained 13TB of data contained on Steam uploaded between the years 2003 and 2013.

"Steam2" here appears to refer to the old name of Steam's server infrastructure, (per Ars Technica)which was upgraded to the modern SteamPipes system in 2013. This data apparently includes early versions and screenshots of games produced by Valve (such as Left 4 Dead 2, Portal 2, and the never-released Half-Life 2: Episode 3).

But this leak doesn't just concern Valve's games. Beta builds of high-profile titles like BioWare and EA's Dragon Age: Origins and Rocksteady and WB Games' Batman: Arkham Asylum were reportedly discovered in the dump.

X user "Gabe Follower" shared screenshots of the leaked data on the platform, and claimed that they verified that there was "no hacking" involved in obtaining the information. The data was reportedly visible after accessing a "publicly accessable [sic] endpoint." It's unclear what endpoint this individual was referring to. Sources speaking to Ars Technica explained that the leak may not have taken place at Valve's end, but rather may be a breach of third-party servers that hosted data gathered during previous leaks.

The contents of such a leak do make for an informative historical look at the early development of Valve's highly-celebrated games, but also raise security questions for other companies whose data was exposed. It's unclear at this time how much sensitive data from third-party publishers was included in the leak, or what the ramifications might be of said data being available to the public.

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About the Author

Bryant Francis

Senior Editor, GameDeveloper.com

Bryant Francis is a writer, journalist, and narrative designer based in Boston, MA. He currently writes for Game Developer, a leading B2B publication for the video game industry. His credits include Proxy Studios' 4X strategy game Zephon, Iron Anchor Studios' Down With The Ship, and Amplitude Studio's 2017 game Endless Space 2.

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