PHP: What is it and why did it spark a global cyber-security scramble?

Researchers using artificial intelligence uncovered serious vulnerabilities in PHP, a programming language used since the 2000s to build websites, including Wikipedia and online shops. The flaws could let attackers take control of web servers without authentication and steal sensitive data. Governments and cyber-security agencies urged website operators to install an emergency fix or take platforms offline. Wikimedia, public bodies in Finland and Scotland, and the BBC were among those that took systems or websites offline as a precaution.