Government agencies and companies worldwide shut down their websites on Wednesday after two critical security vulnerabilities involving the PHP programming language were exposed. Security firm Wiz estimates that PHP powers about 70% of the world's websites and called these vulnerabilities "among the most severe in software history." The U.S. National Security Agency (NSA) has urged organizations to immediately patch or take affected systems offline. Security firm Calif discovered these vulnerabilities in August using OpenAI's GPT-5.6 Sol model, while Wiz also discovered them independently. PHP programmers released a fix patch on Wednesday, and the PHP Foundation urged users to update immediately.