Landmark announcements by some of the biggest names in artificial intelligence (AI) have upended how defenders must think about cybersecurity, vulnerability management and threat detection. In April 2026, Anthropic detailed Mythos Preview, a frontier large language model (LLM) equipped to autonomously find and fix cybersecurity vulnerabilities at scale. Upon launch, Anthropic said that Mythos had already identified thousands of previously undiscovered zero-days. Just days later, OpenAI unveiled GPT-5.4-Cyber, an updated variant of their own GPT-5.4 model fined-tuned to specifically work on cybersecurity problems. The company has since gone onto release an updated version of the model, GPT-5.5-Cyber. For now, both AI companies have restricted their cybersecurity frontier models to a limited audience of approved partners.

Full opinion : How OpenAI and Anthropic’s frontier AI models appear to have upended cybersecurity.