As AI models have become better at finding software flaws and turning them into working attacks, businesses have come under increasing pressure to strengthen their cyber defenses. Gartner forecast in September that worldwide AI cybersecurity spending would reach $51.3 billion this year, nearly double last year’s $25.9 billion.

OpenAI is increasingly leaning into this market, seeing it as an important path to growing its enterprise sales. This is OpenAI’s fourth cybersecurity-focused model this year, following versions released in April, June and August. The company also hired a chief revenue officer, Dali Rajic, who comes from a cybersecurity software background.

Google and Anthropic are also competing for security customers. Anthropic’s Glasswing program gives vetted users access to capabilities that its public models might block. Google, which previously emphasized a lightweight, low-cost model for repeatedly scanning large codebases, has also begun offering vetted defenders access to its frontier Gemini 4 Argon model without cyber guardrails through its Fairwind Program.

OpenAI’s GPT-6 Cyber focuses on advanced vulnerability research and exploit development. To test a server’s defenses, researchers may try breaking into it to see what an attacker could do with a flaw. The same methods can be used in malicious attacks, so general-purpose AI models impose restrictions that can also block legitimate security work. OpenAI has said it trains its Cyber models both to improve specialized cybersecurity skills and reduce refusals for certain tasks that can serve attackers and defenders.

OpenAI tested GPT-6 Cyber on Firefox, Mozilla’s web browser, and the Linux kernel, the core software underlying many servers. Firefox must handle potentially malicious webpages without exposing users’ data, while the Linux kernel controls access to a machine’s resources. Both are open-source projects whose code has been inspected, tested, and hardened by developers and security researchers for years. And yet AI models are still able to find novel vulnerabilities.

OpenAI says researchers used GPT-6 Cyber to find 81 previously unknown, high-severity Firefox vulnerabilities and develop working exploits for 948 Linux kernel vulnerabilities, including 588 previously unknown flaws. The Linux exploits could let an attacker with ordinary local access gain root privileges, the highest level of control over the system. Researchers developed working exploits for more than five times as many Linux vulnerabilities as in a July study using GPT-5.6 Sol, which was considered a state-of-the-art model for cyber tasks when it was released that month.

OpenAI currently offers two levels of access to trusted cybersecurity professionals through its Daybreak program: Daybreak Red supports advanced work such as simulating attacks and building tools that allow for red-teaming, while Daybreak Blue focuses on defensive tasks such as reviewing code, analyzing malware and investigating incidents.

GPT-6 Cyber will initially be available to a select group of approved Daybreak Red customers only, with access expanding to all Red customers over the coming weeks, the company said. Separately, OpenAI said it is expanding early testing of Astra for defensive security work to more organizations and individual security researchers. through Daybreak Blue.