OpenAI launches less restricted GPT-5.4 Cyber model, not in ChatGPT

On 2026-04-15, OpenAI began deploying GPT-5.4 Cyber, a less restricted model tailored for defensive cybersecurity tasks, to vetted security vendors, organizations, and researchers. The model was not made available in ChatGPT and was rolled out under OpenAI’s Trusted Access for Cyber program.