Government websites across Europe and elsewhere were taken offline Wednesday following the discovery of critical vulnerabilities in a widely used programming language, prompting website administrators around the world to scramble to secure their systems.

Developers of the PHP programming language released emergency security patches Wednesday to address vulnerabilities that had remained hidden in the software for years before being uncovered with the help of artificial intelligence (AI). They urged all users to update their systems immediately.

PHP, a programming language that powers as much as 70% of the world’s websites and web applications, disclosed two critical security issues on Tuesday, Oct. 20, that could leave it vulnerable to hackers. The issues would allow bad actors to steal information or launch a cyberattack on anyone visiting a hacked website. PHP software powers WordPress, Drupal, Joomla, and Magento websites, according to a blog post by Huntress cybersecurity researcher John Hammond. "When a critical bug lands in PHP itself, rather than in one app built on top of it, the number of places you have to go looking to identify vulnerable PHP versions gets very big, very fast," he wrote. Get live updates at: https://t.co/jXDYKnhVvh

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As technology companies warned that some hackers were already exploiting the flaws, government agencies across Europe were among those that proactively took their websites offline as a precaution.

The discovery of the security vulnerabilities prompted urgent warnings from governments worldwide, while technology giants including Google, OpenAI and Amazon are involved in efforts to identify the flaws, detect potential attacks and protect affected systems.