Inside OpenAI's Plan To Protect The Internet Before Hackers Break It

Clint Gibler had only been in charge of OpenAI’s elite hacker lab for a few months when a cybersecurity researcher alerted his team to a shocking discovery.

OpenAI’s premier model, GPT-5.6 Sol, had found serious flaws inside PHP, the web programming language that underpins 70% of the websites on the internet today. For more than two months, the AI giant and its collaborators raced behind the scenes to validate the findings and ensure the fixes worked before publicly announcing them this week. A mad scramble ensued to rush out patches across the web as hackers launched millions of attacks to try to exploit the bugs.

The PHP flaws are the first major cybersecurity problems discovered using AI. Over the last year, frontier labs’ AI models have become as good as or better than most experts at finding and exploiting software vulnerabilities. Both OpenAI’s GPT and Anthropic’s Claude, as well as models from startups like Depthfirst, have found a wide array of bugs across browsers and code like PHP that help run the internet. Defenders are now racing to lock down as many of those flaws as possible before hackers use widely available and comparable models — in particular, Chinese open-weight AI like DeepSeek and Kimi — to start breaking into companies at an unprecedented scale. It is perhaps the most pivotal moment in the brief history of cybersecurity.

The warning signs are already here. In September, Forbes reported on Chinese hackers using Anthropic’s Claude and DeepSeek to steal more than 600,000 credit card details. Reuters reported this month on a similar attack that hit another 100 websites. On Wednesday, Microsoft said Chinese hackers used an agentic AI tool called Artex, typically used in cybersecurity testing, to attack hundreds of organizations, including government and military targets.

Not that it’s making customers feel 100% safe. “The concerning thing is that attackers are going to be able to do a lot of this too,” Nettesheim says.