OpenAI CEO Sam Altman Teases GPT-5.5 Cyber AI Model Rollout, Could Take On Anthropic’s Claude Mythos

OpenAI CEO Sam Altman teased the successor to the GPT-5.4 Cyber artificial intelligence (AI) model on Thursday. Dubbed GPT-5.5 Cyber, the model was announced just a fortnight after the San Francisco-based AI giant introduced its first cybersecurity model. Not a lot is known about the model currently, but it is expected to follow the same limited release format as the predecessor. The model is said to be competing with Anthropic's Claude Mythos, and offers similar real-world vulnerability detection prowess.

OpenAI Teases GPT-5.5 Cyber

In a post on X (formerly known as Twitter), Altman shared that GPT-5.5 Cyber will soon be rolled out to critical cyber defenders. Interestingly, the company is also hosting a GPT-5.5 “party” at its San Francisco headquarters on May 5. The company had asked users to sign up to get a chance to attend it. There's a possibility that OpenAI might preview some of the capabilities of 5.5 Cyber during the event.

For now, not a lot is known about the large language model (LLM). Besides teasing the early access rollout, the OpenAI CEO said, “We will work with the entire ecosystem and the government to figure out trusted access for cyber; we want to rapidly help secure companies/infrastructure.”

The restricted rollout makes sense. When the company released the GPT-5.4 Cyber model, it was designed for cybersecurity functions. It used binary reverse engineering capabilities to analyse compiled software for malware potential, vulnerabilities, and overall security. OpenAI had said that the model does not even require access to the source code of a software to analyse this.

Based on this, it appears that the model's functionality is broadly similar to Anthropic's Claude Mythos. To ensure that the cybersecurity LLM would not be misused, the AI giant scaled its Trusted Access for Cyber (TAC) programme, which only lets the model be accessed by verified individuals and firms.

Since little is known about the capabilities of the GPT-5.5 Cyber AI model, it cannot be said with certainty that it can outperform Claude Mythos. However, once OpenAI releases the system card and internal evaluations, the comparison between the two will become clearer.