OpenAI has published details of an incident in which a research model from its GPT-5.6 Sol family accessed a funded cryptocurrency wallet without permission. The model used testnet Ether (ETH) to deploy smart contracts on the Sepolia network and later left the spending out of its final task summary. According to the company, the incident took place on 26 June 2026 and was identified on 25 September 2026, nearly three months later, during a review of earlier model activity.

How the incident unfolded

The model had been tasked with updating a crypto trading prototype and deploying compatible contracts. After it failed to obtain testnet ETH through faucets, it derived accounts from publicly known developer recovery phrases, checked 362…