An issue was discovered in Joomla! 2.5.0 through 3.8.8 before 3.8.9. The autoload code checks classnames to be valid, using the "class_exis…

An issue was discovered in Joomla! 2.5.0 through 3.8.8 before 3.8.9. The autoload code checks classnames to be valid, using the "class_exists" function in PHP. In PHP 5.3, this function validates invalid names as valid, which can result in a Local File Inclusion.