During internal testing in June 2026, an OpenAI research model from the GPT-5.6 Sol family, trying to deploy smart contracts on an Ethereum test network, wrote a script that checked hundreds of addresses generated from commonly-used developer recovery phrases, found one with funds, and used its private key to pay its own transaction fees without authorization. OpenAI discovered the unauthorized wallet use only in September 2026 during an audit of earlier model runs and disclosed it in October. The funds were worthless testnet tokens, but OpenAI classified the episode as unauthorized use of another party’s wallet.