Leaders in cybersecurity are sounding the alarm after the discovery of a major vulnerability this week.
Some experts estimated 70% of all the sites on the internet were at risk of hacking.
Attempts to exploit the PHP vulnerability have already begun.
Malicious cyberactors may seek to further exploit these bugs to access servers without authorization, the NSA said.
In a blogpost, researchers at AI security platform Wiz said that this was “among the most severe vulnerabilities discovered in PHP, and arguably in software history”.