A global cyber-security alert has been issued after artificial intelligence uncovered serious, long-standing vulnerabilities in PHP, the programming language that powers a significant portion of the internet. Governments and cyber-security agencies worldwide are now scrambling to address the fallout from the discovery, which was made public on Wednesday.

PHP, which stands for PHP: Hypertext Preprocessor, is an open-source, back-end programming language developed in the early 1990s. It is instrumental in creating dynamic web pages and applications, underpinning widely used platforms such as Wikipedia, online shops, and WordPress. When users visit a website, PHP code processes data on the web server to generate the visible page.

Cyber-security firm Wiz, whose researchers were instrumental in identifying the flaws, described them as the most severe ever detected by AI. OpenAI, the company whose technology was used in the discovery process, characterized the vulnerabilities as one of the most impactful security issues in recent memory. The vulnerabilities, dubbed php2shell, are inherent to the language itself and affect versions of PHP released over the past decade.

Researchers warn that under specific conditions, malicious actors could exploit these flaws to gain control of affected web servers, potentially leading to the theft of sensitive data. The use of AI could also accelerate and simplify the execution of such attacks, according to Paul Spain, chief executive of Gorilla Cyber Security. He estimates that millions of websites could be impacted.

PHP is estimated to power 70% of the world's websites and is maintained by the non-profit PHP Foundation. The discovery of these vulnerabilities has led to urgent calls for website operators to install an emergency fix or, in some cases, consider temporarily taking their platforms offline to prevent potential exploitation.

Ryan Austin, a researcher at Calif, one of the firms involved in the disclosure, stated that this was the most serious vulnerability he had ever found. Wiz highlighted in a blog post that the php2shell issue left "everything built on PHP exposed" when exploited under the right conditions.

The implications of these vulnerabilities are far-reaching, with potential impacts on a wide range of online services. Jill Slay, a cyber-security researcher at the University of Adelaide, expressed concern that if hackers or state actors weaponized these flaws, it could lead to the seizure of vast amounts of private data from websites.

The alert has already caused disruptions across various online sectors, affecting services ranging from gaming platforms and government portals to online forums. The sheer ubiquity of PHP means that patching and securing affected systems present a significant global challenge for website administrators and cyber-security professionals.