Key facts
- OpenAI said the model found 81 previously unknown Firefox vulnerabilities that Mozilla classified as high severity.
- OpenAI said the model helped develop working exploits for 948 Linux kernel vulnerabilities, 588 previously unknown.
- OpenAI said it disclosed 304 critical Linux findings to maintainers along with proposed patches.
- OpenAI raised the model's cybersecurity classification to "Critical" from "High" for GPT-5.6 Cyber.
- GPT-6 Cyber is available to select Daybreak Red customers, with wider access planned over the coming weeks.
OpenAI released GPT-6 Cyber, a model built to find and exploit security flaws, to a small group of vetted customers on November 5, 2026, rating it "Critical" in cybersecurity under its safety framework. The company said the model is meant to help security researchers find vulnerabilities, test how they could be exploited and fix flaws before attackers do.
OpenAI said its researchers used the model to find 81 previously unknown Firefox vulnerabilities that Mozilla classified as high severity, and that Mozilla has begun releasing fixes. It also said the model helped develop working exploits for 948 Linux kernel vulnerabilities, including 588 that were previously unknown, and that the company disclosed 304 critical Linux findings to maintainers along with proposed patches.
The "Critical" rating is an increase from "High" for GPT-5.6 Cyber. OpenAI said it is seeing more attempts to misuse AI, including by malicious cyber actors and groups seeking to distill its models.
GPT-6 Cyber is available to select customers of Daybreak Red, OpenAI's access tier for advanced, authorized security work such as penetration testing and exploit development. OpenAI said access will be expanded to all approved Daybreak Red customers over the coming weeks, and that GPT-5.6 Cyber is being made available to all Daybreak Red customers starting November 5, 2026.