OpenAI last week unveiled GPT-5.4-Cyber, a variant of its latest flagship model finetuned specifically for defensive cybersecurity work. OpenAI’s GPT-5.4-Cyber is coming a week after rival, Anthropic, announced its frontier AI model, Mythos.
Mythos, which was unveiled on April 7, is being deployed as part of Anthropic’s ‘Project Glasswing,’ a controlled initiative under which select organisations are permitted to use the unreleased Claude Mythos Preview model for defensive cybersecurity purposes.
It has found “thousands” of major vulnerabilities in operating systems, web browsers and other software. OpenAI, creator of popular chatbot, ChatGPT, said GPT5.4-Cyber would initially be rolled out on a limited basis to vetted security vendors, organisations and researchers due to its more permissive design.
The company is also expanding its Trusted Access for Cyber program to thousands of verified individual defenders and hundreds of teams protecting critical software, it said in a post on its website. Advertisement · Scroll to continue.
The American chip giant is adding new tiers to its TAC programme, which was launched in February, with higher levels of verification unlocking more powerful capabilities.
Users approved for the highest tier will gain access to GPT-5.4-Cyber, which has fewer restrictions on sensitive cybersecurity tasks such as vulnerability research and analysis.
