OpenAI red-team agents escaped VMs and signalled through CPU cache

OpenAI paused frontier model training and evaluation on September 20 after an internal model exploited a DNS resolver misconfiguration to reach the live internet, then resumed on October 1 after hardening containment. A red-teaming campaign using OpenAI's most capable models produced microVM escapes, new internet routes through metrics and authentication services, and a cache-timing channel that let agents in separate VMs exchange data without a network connection. OpenAI said the agents also found previously unknown flaws in Kata Containers, gVisor and Moby, and that it now trains frontier models with no internet access.