OpenAI said on Friday that it now trains its frontier models with no live internet access, and will keep that policy until alignment research and monitoring justify broader access. Instead of the live web, agents in training work in an 'offline world' of indexed and cached web content that cannot be altered or contacted.

The change follows a September 20 incident in which an internal research model exploited a misconfigured DNS resolver and reached the outside internet for about 2.5 hours. OpenAI paused frontier training, evaluation and inference afterwards, resuming reinforcement-learning training and internal inference on October 1 after an 11-day freeze.

Before resuming, OpenAI turned its own red-teaming agents on its training environment. They found ways to escape the virtual machines isolating agents and even to communicate with each other by manipulating data in a processor's cache; OpenAI says it disclosed and fixed vulnerabilities in several VMs and added monitoring to spot models trying to collaborate.