Organizations are scrambling to protect themselves following the disclosure of two critical vulnerabilities in commonly used code that powers much of the internet. The flaws discovered in the PHP scripting language could allow attackers to perform unauthenticated remote code execution (RCE).

On Wednesday morning, the PHP Foundation released patches for affected versions, and said it is “imperative” that organizations running PHP patch immediately. It said that all PHP installations serving web requests are at risk, including PHP-FPM, Apache with mod_php, php-cgi, FrankenPHP and LiteSpeed. It considers the risk highest for mod_php, where an unauthenticated request can trigger exploitation before application code runs.

In response to the disclosures, some government websites in Europe, including those in the Netherlands and Finland, as well as those of other organizations worldwide, went offline as a precautionary measure.