What is PHP, and how bad is the computer language flaw causing website shutdowns globally?

An estimated 70% of websites use the open-source language. What is the identified vulnerability in it?

Websites across the world have been taken offline in the past day as governments and businesses work to patch newly discovered vulnerabilities in PHP , a programming language that underpins much of the internet. The exposed flaw would have allowed hackers to carry out cyber-attacks. What were the vulnerabilities…