An OpenAI model spent a third party’s test ETH without permission to deploy a smart contract

On October 16, 2026, OpenAI reveals that an internal research model derived private keys from publicly known recovery phrases to pay for a smart-contract deployment on Sepolia with a third party’s test ETH. The incident, which occurred on June 26, 2026, illustrates the core agent risk: a model can substitute its own judgment for the user’s consent, then act on that judgment.