On October 13, 2026, security company XBOW disclosed that its researchers and AI agents had assembled a three-vulnerability Chrome exploit chain during a six-day sprint in August. XBOW says Google awarded the company $250,000 for the work. The sprint ran August 2–7, after an earlier challenge and a first full-chain attempt that took two months. XBOW’s announcement and technical account describe how the chain joined flaws in V8, animated-WebP decoding, and Crashpad.
The six-day sprint followed earlier work
The six days refer to the awarded chain, not the start of the research. XBOW says Oege de Moor set the challenge in January 2026. The company’s first full-chain submission took two months; Google told XBOW it already knew about one bug in that attempt. Backup components let the researchers replace it before assembling the chain that earned the award, according to XBOW’s account.
XBOW dates the awarded sprint to August 2–7, during Black Hat and DEF CON in Las Vegas. It estimates that the campaign used about $40,000 in compute and API charges, based on its usage logs. XBOW also says Google awarded it $250,000 under Chrome’s full-chain vulnerability reward program.
How the three Chrome components fit together
XBOW describes a sequence across three parts of Chrome’s security architecture. V8, Chrome’s JavaScript engine, was the first stage: a compiler flaw enabled memory access within V8’s protected area, which XBOW calls its cage. A flaw in animated-WebP decoding then allowed a native write outside that area. Finally, a memory-safety bug in Crashpad, Chrome’s crash handler, helped the chain reach code execution outside the renderer sandbox. That sandbox isolates the browser process that handles web content.
The distinction matters: the reported result depended on linking separate flaws across security boundaries, rather than on one bug doing everything. XBOW says a crafted web page could have led to code execution on a Windows machine without a click or download. This is the capability XBOW attributes to its research chain.
Google’s September 3 Chrome release notice identifies CVE-2026-85045 as a high-severity V8 race condition and lists Chrome versions 152.0.7977.82 and 152.0.7977.83. Google’s release notice supports that V8 mapping; XBOW’s technical account describes the broader three-stage chain.
What the agents did—and what researchers did
XBOW says its agents searched source code, tested ideas, built proofs of concept, and drafted exploit stages. Researchers selected targets, supplied context, reviewed and redirected the agents’ work, and chose which components to combine. The account names Brendan Dolan-Gavitt, Andres Luksenberg, Baul Lee, and Willem Pinckaers as the researchers assigned to the challenge; it describes GPT-5.6 Sol and earlier models as part of the team.
That division helps explain what the six-day figure represents: AI agents contributed to specific research tasks, while people made the decisions about targets, review, and how to assemble the chain. XBOW’s account describes this project, not a universal template for AI-assisted security research.
What XBOW says Chrome users should do
XBOW says all three flaws have been fixed and advises restarting Chrome after an update so the fix takes effect. Google’s September 3 notice identifies the V8 issue and the Chrome versions listed there; XBOW’s broader patch guidance applies to its reported chain.
