OpenAI announced on October 21, 2026, that GPT-5.6 Sol, one of its most advanced AI models, had identified critical vulnerabilities in PHP, a widely used open-source programming language. The discovery was made through the company’s cybersecurity initiative, Patch the Planet. OpenAI called the flaws among the most impactful security issues in recent memory, citing PHP’s extensive use in websites and web applications.
The discovery involved a coordinated effort with security firms Wiz and Cloudflare, as well as PHP’s maintainers, to prepare fixes before public disclosure. OpenAI said it has already found several other significant vulnerabilities and expects such discoveries to increase sharply. The findings highlight the dual nature of advanced AI: it can help identify major security flaws, but it also has potential for malicious use. OpenAI is increasing access to its tools for security defenders.