OpenAI GPT-5.5-Cyber in Preview for Critical Infrastructure Defenders
OpenAI is rolling out GPT-5.5-Cyber — GPT-5.5 with Trusted Access for Cyber (TAC) — in a limited preview for organizations responsible for securing critical infrastructure. Sam Altman described it as "the best option for developers to find and patch vulnerabilities in their code" and framed the release as an urgent safety initiative: "we'd like to help companies secure themselves and we think it's important to start work on this quickly."
Why It Matters
The limited preview directly competes with Anthropic's Claude Mythos, which Mozilla used to fix more Firefox bugs in April than the previous 15 months combined. Security-focused AI capabilities are now a top-line differentiation battleground between the two leading labs.