Security researchers spent 6 days doing their Chromework, built 1B user exploit

Xbow chained three Chrome zero-days with GPT-5.6 Sol into a Windows sandbox escape affecting about one billion users.

Xbow researchers used OpenAI's GPT-5.6-Sol model to help chain three Chrome zero-days into code execution outside the browser sandbox on Windows, a chain they estimate could affect about one billion users. The stages are a Maglev compiler bug giving read and write access inside V8's pointer-compression cage, an animated-WebP decoder bug used to escape the V8 sandbox, and a Crashpad overflow that crosses the outer process sandbox. Google fixed all three issues, paid a $250,000 bounty, and users need Chrome 152.0.7977.82 or later after relaunching. The team spent six days and about $40,000 in token charges; humans chose targets and chained stages while agents searched code and built proofs of concept.

• Three Chrome zero-days were chained: Maglev, animated WebP, and Crashpad.
• The chain escapes the V8 and OS sandboxes for unsandboxed Windows code execution.
• Xbow estimates roughly one billion Chrome users could have been affected.
• Google patched all three; users should run Chrome 152.0.7977.82 or later.
• Researchers spent six days and about $40,000 in tokens and received $250,000.