XBOW just collected Google's first $250,000 Chrome full-chain bounty under the Vulnerability Reward Program rules Google set in April. The company says one researcher, working with AI agents on OpenAI's publicly available GPT-5.6 Sol model, turned a normal webpage into code execution outside Chrome's Windows sandbox in six days. Compute for the winning chain ran about $40,000.
The attack crossed three stages. A bug in Maglev, V8's mid-tier compiler, gave memory control inside the JavaScript engine. An animated WebP decoder flaw turned that into a single write outside the V8 cage. A Crashpad memory-read bug in the unsandboxed crash handler finished the escape. Google's engineers reproduced a demo that launched Calculator from a page in Chrome Beta, then shipped fixes. XBOW says the bugs were never used against users and puts about a billion Windows Chrome installs in the blast radius before the patches.
The first chain they tried hit a collision when Google already knew one of the bugs. Modular staging let them swap in the WebP stage and still land the award. CEO Oege de Moor's pitch is blunt: attackers already move this fast, so defenders need the same tools pointed at their own code. Keep Chrome current and restart it when the update prompt shows up. The fix only sticks after a relaunch.
— via XBOW, Business Wire.