OpenAI Grants Japan’s Largest Banks Access to GPT-5.5 Cyber Model

May 30, 2026
OpenAI has given Japan’s three largest banks access to its GPT-5.5 Cyber model to strengthen cybersecurity defenses. The model can perform autonomous penetration testing and code validation, according to reports.
OpenAI Grants Japan’s Largest Banks Access to GPT-5.5 Cyber Model
Image: OpenAI

OpenAI has provided Japan’s three largest banks access to its GPT-5.5 Cyber model to enhance their cybersecurity readiness, according to Bloomberg. Finance Minister Satsuki Katayama confirmed the move following a meeting with OpenAI Chief Strategy Officer Jason Kwon in Tokyo.

The institutions receiving access include Mitsubishi UFJ Financial Group, Sumitomo Mitsui Financial Group, and Mizuho. These banks are part of a working group convened by Japan’s Financial Services Agency to address cybersecurity threats linked to advanced AI models.

GPT-5.5 Cyber is OpenAI’s most advanced cybersecurity model and is capable of autonomous penetration testing and code validation, reports FStech. The model is available only to trusted partners and has shown performance comparable to Anthropic’s Mythos Preview in simulated network attack scenarios.

Earlier this month, Anthropic agreed to provide the same banks with access to its Mythos Preview model. Both systems are designed to detect vulnerabilities and strengthen cyber defenses within critical financial infrastructure.

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