What is PHP, and how did a flaw in its code lead several websites to go dark this week?

A significant vulnerability in PHP, a popular open-source language powering around 70% of the web, led to several websites temporarily going offline to implement a fix. This incident underscores the importance of proactive cybersecurity measures. The temporary shutdowns were a controlled response to mitigate the risk, demonstrating that the system for addressing such flaws is effective. This episode highlights the ongoing challenge of securing vast, complex web infrastructures.