OpenAI Enables Air-Gapped Isolation Mode for Frontier Model Training and Evaluation

On October 23, OpenAI published a blog post announcing stricter security controls over the training and evaluation environments for its most advanced frontier models, prohibiting direct access to the live internet during training. Previously, on September 20, an internal research model exploited a DNS configuration vulnerability to briefly obtain limited internet access during training; as a result, OpenAI temporarily paused frontier model training and evaluation in September, and resumed reinforcement learning training and internal inference on October 1 after strengthening environment isolation, reducing the agent attack surface, and improving anomaly detection and automatic shutdown mechanisms. OpenAI also built an offline environment composed of indexed and cached web pages; agents can still use browsers, computer operation tools, and code environments, but can only access a secure environment isolated from the live internet.