OpenAI said that 70% of the world's websites could be in peril after cybersecurity researchers using its AI models found exploits in a popular programming language.
The National Security Administration's cyber division advised all web providers that use PHP, a widely used open-source language, to take their systems offline or update their software after OpenAI said one of its models found two "critical" flaws in the language's infrastructure.
Greg Brockman, the president of OpenAI, said in an X post that hackers could exploit the vulnerability to steal private user data or modify websites.
"We consider this one of the most impactful security issues in recent memory," OpenAI said in a blog post.
While OpenAI said the vulnerabilities appear to have been identified before any attackers discovered them, the public disclosure set off a race for companies and governments to update their websites and apply fixes before hackers could exploit the bugs. "We are seeing early attacks emerging and are updating mitigations as new vectors show up," Dane Knecht, Cloudflare's chief technology officer, said in a post on X.
Numerous websites, including those belonging to governments and the media, went offline on Wednesday to address the issue.
PHP is a popular programming language that often handles the behind-the-scenes work powering websites that require user logins and online orders.
The critical flaw was first identified by Calif, a cybersecurity research company using GPT-5.6 Sol. Wiz, another cybersecurity company, independently uncovered the issues, OpenAI said. The companies are part of an OpenAI-led initiative called "Patch the Planet," which aims to make the world's digital infrastructure more secure.
The public disclosure on Wednesday by OpenAI and others of the existence of the exploits triggered urgent messages from leaders worldwide, including the Japanese Prime Minister.
"We have an urgent request for everyone to take action tonight," said Sanae Takaichi.