# XBOW: AI agents built a Chrome full-chain exploit in six days

> Four XBOW researchers directed AI agents running a public OpenAI model to build a working Chrome exploit chain in six days.

- **Severity:** Info: Research, tools, evals or lab claims with no direct exposure. Context, not an alert.
- **Category:** Research
- **Published by:** XBOW
- **Disclosed:** 2026-10-13
- **Affects:** Google Chrome
- **Research by:** Oege de Moor, Brendan Dolan-Gavitt, Andres Luksenberg, Baul Lee, Willem Pinckaers
- **Primary source:** https://xbow.com/blog/xbow-built-a-chrome-full-chain-exploit
- **Page:** https://theinjection.dev/items/xbow-chrome-full-chain/

XBOW reports that four of its researchers directed AI agents running OpenAI's publicly available GPT-5.6 Sol to build a three-stage Chrome exploit chain in six days, and that Google paid its top $250,000 full-chain reward.

## What happened

XBOW published the result on October 13, 2026, after Google awarded it the top $250,000 Chrome reward for a full exploit chain. Oege de Moor writes that Brendan Dolan-Gavitt, Andres Luksenberg, Baul Lee and Willem Pinckaers rebuilt the chain between August 2 and August 7, 2026, in Las Vegas during Black Hat and DEF CON. An earlier attempt was disqualified because Google already knew one of its bugs.

## How it works

The chain is three independent stages, each with a spare bug, so the team could swap a stage out when Google said a flaw was already known. AI agents running GPT-5.6 Sol and earlier OpenAI models searched Chrome's source code, tested ideas, built proofs of concept and wrote the first exploit drafts. The four humans set the strategy, chose where to look, checked the agents' work and redirected them on the results. XBOW does not publish the bug details or any CVE ids in this post.

## Who is affected

Chrome users on Windows were the target. XBOW's post is titled around a chain affecting a billion users, and describes an attacker using Chrome to take over a Windows machine remotely. XBOW states that all three bugs are fixed and that the exploit was never used against Chrome users.

## What to do

Update Chrome and relaunch the browser, which is XBOW's own advice to readers: a staged update only takes effect after a restart.

## Quick facts

- **Reward:** $250,000, Google's top Chrome full-chain award
- **Model used:** OpenAI GPT-5.6 Sol and predecessors, publicly available
- **Build time:** Six days, August 2 to 7, 2026
- **Compute cost:** About $40,000, XBOW's figure
- **Target:** Google Chrome on Windows
- **Found by:** Four XBOW researchers directing AI agents
- **Status:** All three bugs fixed, per XBOW

## Sources

1. [XBOW Write-Up](https://xbow.com/blog/xbow-built-a-chrome-full-chain-exploit)
2. [Chrome VRP FAQ](https://chromium.googlesource.com/chromium/src/+/main/docs/security/vrp-faq.md)