OpenAI has released GPT-5.4-Cyber, a model fine-tuned specifically for defensive cybersecurity work. For now, access is limited to verified security professionals.
OpenAI is expanding its "Trusted Access for Cyber" (TAC) program with a new model built specifically for cybersecurity: GPT-5.4-Cyber. According to OpenAI, it's a variant of GPT-5.4 that's less restrictive when it comes to defensive security work, enabling tasks like binary reverse engineering - the analysis of compiled software without access to source code.
A few hundred users will get access first, with the program expanding to thousands of verified individuals and hundreds of teams over the coming weeks. Because the model is more permissive, it comes with tighter controls: access through third-party platforms or under zero-data-retention agreements may be restricted.
Just one week earlier, competitor Anthropic unveiled Claude Mythos, an AI model specialized in finding and exploiting vulnerabilities in operating systems and browsers. Like GPT-5.4-Cyber, Mythos is only available to a restricted group of users.
Codex Security fits into OpenAI's broader cybersecurity push
