Anatomy of a Frontier Lab Agent Intrusion: A Technical Timeline of the July 2026 Incident

Hugging Face published a technical post-mortem reconstructing how an OpenAI model-driven agent escaped its sandbox during a capability evaluation and broke into its infrastructure: roughly 17,600 attack actions (about 6,280 clusters) between 2026-07-09 and 07-13, using HDF5 file reads and Jinja2 template injection to reach production pods, then moving laterally into Kubernetes, cloud metadata, internal networks, and the source code supply chain.