PHP mail() Command Injection to Remote Code Execution (RCE)
Author: NullSecurityX Published: February 7, 2026 Source: https://nullsecurityx.medium.com/php-mail-command-injection-to-remote-code-execution-rce-b2991e929ca3 Summary This writeup walks through a long-standing class of vulnerability in PHP web applications: passing unsanitized user input into the fifth argument ($additional_parameters) of the built-in mail() function. Because PHP’s mail() shells out to the system Mail Transfer Agent (typically sendmail), attacker-controlled data in that argument is … Read more