Governments and companies around the world are racing to fix vulnerabilities revealed by artificial intelligence that could affect 70% of the world’s websites.
Some websites and services briefly went dark after the set of vulnerabilities were announced Wednesday.
The US National Security Agency and Europe’s cybersecurity agency advised companies to take immediate action to address two critical flaws in PHP, a programming language that powers 70% of the world’s websites.
The flaws in PHP were uncovered and addressed by teams at OpenAI, Google-owned cybersecurity company Wiz, and another cybersecurity company, Calif. The underlying flaws had existed for a decade, but exploiting them involved a complex set of steps “at the edge of what human researchers could practically achieve,” according to Wiz. Researchers then deployed AI to adapt techniques for taking advantage of those vulnerabilities – known as as “exploits” in cybersecurity – and analyze the results.
The bugs, collectively called PHP2Shell, could allow attackers to break into websites and read memory that could contain sensitive information, like passwords.
The PHP Foundation, the organization behind the coding language, has released a patch for the bugs, which have been hidden in their software for years, and is urging website operators to update their systems immediately. The CEO of Cloudflare said on X that his company’s network has observed millions of attempts to exploit the vulnerabilities in the past couple of days.
“With PHP behind such a vast share of the web, the exposure could reach almost everywhere people spend money online,” said Nigel Green, the CEO of deVere Group, a financial advisory firm.
“Booking platforms, marketplaces, subscription services, ticketing sites, delivery apps and utility portals could all be holding card details on systems built with the same kind of code,” he added.
The vulnerabilities involve an issue with how the PHP language works with a computer’s memory. When a website request unexpectedly ends, PHP could leave data behind in the memory that can be accessed and potentially corrupted or exposed later.
The bugs were discovered in late August but were disclosed to the public only on Wednesday, after PHP had come up with a fix.
AI played a crucial role in identifying and fixing vulnerabilities “that had remained hidden in the PHP codebase for more than a decade,” according to Wiz. The company called PHP the “backbone of the web” and said the episode marks an AI inflection point.
“What AI changed was the ability to understand the weaknesses,” Wiz researchers wrote in a blog post Wednesday, and then quickly exploit those weaknesses into a way to attack.
“With frontier AI models and the right tools, a single researcher completed in a week what previously would have taken a world-class team months of work,” they added.
The flaws could allow attackers to remotely execute code, disrupt services and expose customer data, according to web infrastructure provider Cloudflare, which has been working with the PHP Foundation, Calif, OpenAI and Wiz to address the issue.
Researchers at Wiz used Google’s Gemini 4 Argon, Wiz Atlas and OpenAI’s GPT-5.6 Sol during the research process.
Global leaders urged organizations to take action. Dutch Prime Minister Rob Jetten said that his cabinet was “closely monitoring the situation surrounding the vulnerabilities in PHP.”
Japan’s Prime Minister Sanae Takaichi said companies should consider suspending services if necessary in order to reduce their exposure. “Please check if your publicly available websites use PHP, and prepare to apply the fix patch that will be released tonight… as soon as possible,” she posted on X Wednesday.
Japanese airline ANA, railway operator JR West and the country’s largest bank, MUFG, were among companies that reported some webpages and services temporarily suspended.
In Europe, government websites in France, Denmark, Finland and the Netherlands, including the Dutch cyber security agency, were temporarily taken offline while security fixes were implemented.
The Wikimedia Foundation, the non-profit that operates Wikipedia, told CNN Thursday that it was “in the process of addressing security vulnerabilities in PHP,” and that a number of its systems had been taken down as a “precautionary measure.”
Nearly three dozen UK government services are unavailable and four are “partially unavailable” while security upgrades take place, UK government minister Elizabeth Lloyd told the House of Lords Thursday. The Journal, Ireland’s second most-popular news outlet, was temporarily offline Thursday morning while it bolstered its “defences,” it said in a notice.
Wiz researchers say the issue is on par with the Heartbleed bug from 2014, which impacted an encryption technology estimated to be used by some two-thirds of the Web. Heartbleed allowed cybercriminals to access data that should have been protected.
Like Heartbleed, the researchers at Wiz say PHP2Shell could similarly serve as a turning point in cybersecurity. While the vulnerabilities existed for years, AI made it practical to deploy them.
“The underlying flaws had been present for decades, but demonstrating their exploitability required an exceptionally complex chain of steps, at the edge of what human researchers could practically achieve,” the researchers said.
“Frontier AI models substantially reduced that barrier, turning a longstanding flaw into an exploit.”
– CNN’s John Liu, Anna Cooban, Amy Croffey and James Frater contributed reporting.