open_basedir INI setting is enabled

The open_basedir configuration adds a thin layer of security to PHP, especially when different applications are running on the same server. However using open_basedir can decrease the performance of an application, because it disables the realpath cache and generally makes PHP I/O functions slower.

There are security options on the Linux operating system level that are much more suitable than open_basedir such as chroot, dedicated servers, virtualization or containerization.