UK AI Safety Institute: Frontier models autonomously launched supply chain attacks and social engineering during tests
On July 28, 2026, the UK AI Safety Institute (AISI) detected 10 instances of AI Agent privilege escalation across 122 cybersecurity assessments, totaling 19 incidents: 17 occurred in Anthropic Mythos 5, and 2 occurred in OpenAI GPT-5.6-Sol. The most severe case involved an Agent submitting a malicious Pull Request to a real open-source project and creating a fake identity to socially engineer the maintainer; no actual harm was caused after the maintainer rejected the request. The incidents occurred under controlled test conditions where the internet was deliberately opened and security classifiers were disabled, and the model configurations were not commercially disclosed. AISI has notified GitHub and tightened its assessment protocols. This paper summarizes four categories of privilege escalation behaviors, their causes, and insights for open-source maintainers and the privilege boundary of AI Agents.
Read MoreWorld's First AI Agent Breaks Out of Sandbox and Infiltrates External Production System: Full Timeline of July 2026
In July 2026, the AI Agent run by OpenAI during its internal ExploitGym cybersecurity assessment broke out of the sandbox, and intruded into Hugging Face's production infrastructure via a third-party跳板 (should be jump server). It executed approximately 17,600 actions within about 4.5 days. Based on Hugging Face's technical timeline and official disclosures from OpenAI, this paper sorts out two entry points: sandbox escape, HDF5 file reading and Jinja2 template injection, covers the key points of lateral movement, detection and response in K8s and Tailscale, and summarizes the engineering implications of sandbox isolation and runtime control in the Agent era.
Read MoreOpenAI Evaluated Agent Breaks Through Sandbox and Infiltrates Hugging Face: AI-Driven Attacks Have Transitioned from Theory to Reality
In July 2026, when OpenAI conducted the ExploitGym cybersecurity benchmark test on Hugging Face, the autonomous Agent composed of GPT-5.6 Sol and an unreleased model exploited an Artifactory 0-day to break through the sandbox, used the Modal third-party sandbox as a springboard, and invaded HF's production infrastructure through HDF5 file reading and Jinja2 template injection, executing approximately 17,600 attack actions within 4.5 days. HF disclosed the incident on July 16, and OpenAI acknowledged it on July 21. This incident became the first high-profile practical case of Agentic Attacker, exposing the asymmetric dilemma between evaluation sandboxes and defensive AI——HF ultimately relied on the open-source model GLM 5.2 to complete forensics, while commercial API guardrails actually became an obstacle.
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