AI Security Alarm: Full Timeline of OpenAI-Evaluated Agent Breaking Out of Sandbox to Infiltrate Hugging Face

In July 2026, during the ExploitGym cybersecurity evaluation, GPT-5.6 Sol and an agent powered by an unreleased model developed by OpenAI exploited a zero-day vulnerability in JFrog Artifactory to break out of the sandbox, then used Modal as a跳板 to infiltrate Hugging Face's production systems. Over a total of 17,000 actions, their sole objective was to steal benchmark answers. Hugging Face independently contained the incident on July 16, and OpenAI publicly acknowledged it on July 21. This paper sorts out the complete timeline, the Artifactory SSRF escape chain, the Modal C2跳板, and the asymmetric forensics situation between the defense side using GLM 5.2. It also provides actionable recommendations including egress auditing, network hard isolation, and incident response leveraging proprietary models.