## OpenAI Launches GPT-5.4-Cyber for Enhanced Security **OpenAI** on Tuesday unveiled **GPT-5.4-Cyber**, a variant of its latest flagship model, **GPT‑5.4**, that's specifically optimized for defensive cybersecurity use cases, days after rival **Anthropic** unveiled its own frontier model, **Mythos**. "The progressive use of AI accelerates defenders – those responsible for keeping systems, data, and users safe – enabling them to find and fix problems faster in the digital infrastructure everyone relies on," **OpenAI** said.  ## Expanding Trusted Access for Cyber Defense In conjunction with the announcement, the artificial intelligence (AI) company said it's ramping up its Trusted Access for Cyber (**TAC**) program to thousands of authenticated individual defenders and hundreds of teams responsible for securing critical software. ## Addressing Dual-Use Concerns AI systems are inherently dual-use, as bad actors can repurpose technologies developed for legitimate applications to their own advantage and achieve malicious goals. One core area of concern is that adversaries could invert the models fine-tuned for software defense to detect and exploit vulnerabilities in widely-used software before they can be patched, exposing users to significant risks. **OpenAI** said the goal is to democratize access to its models while minimizing such misuse, as well as strengthening its safeguards through a deliberate, iterative rollout. The idea is to enable responsible use at scale, give defenders a head start, and simultaneously shore up guardrails against jailbreaks and adversarial prompt injections as model capabilities become more advanced. "As model capabilities advance, our approach is to scale cyber defense in lockstep: broadening access for legitimate defenders while continuing to strengthen safeguards," the company added. ## Codex Security's Impact The **ChatGPT** maker, which launched **Codex Security** as a way to find, validate, and propose fixes for vulnerabilities, revealed that the AI-powered application security agent has contributed to over 3,000 critical and high fixed vulnerabilities. ## Anthropic's Mythos and Project Glasswing **OpenAI's** limited release follows the preview of **Anthropic's Mythos**, a frontier model that's being deployed in a controlled manner as part of Project **Glasswing**. The model, the company said, found "thousands" of vulnerabilities in operating systems, web browsers, and other software. ## Shifting Security Left "The strongest ecosystem is one that continuously identifies, validates, and fixes security issues as software is written," **OpenAI** said. "By integrating advanced coding models and agentic capabilities into developer workflows, we can give developers immediate, actionable feedback while they are building, shifting security from episodic audits and static bug inventories to ongoing, tangible risk reduction."