OpenAI has disclosed a cybersecurity incident during an external evaluation of its frontier AI models that reached Hugging Face's production infrastructure. The company says the activity occurred in ExploitGym, an internal evaluation environment designed to be highly isolated, and has prompted a stronger focus on containment, monitoring, and safeguards for third-party testing. In its official account of the Hugging Face model evaluation security incident , published July 21, 2026 and updat...