I think it may not be possible, even though there is a trick can execute an executable on noexec partition. But it is just a hack, may be disabled in later release.
To better deal with vnlerable scripts, my suggestion is to harden the security on your server as much as you can, and chroot if you can, even when they upload some bad scripts, the script may not able to execute in a chroot jail due to missing system commands or someting. Even when the script get executed, it will not able to do harm to your system files.
LSWS provides you such a platform that you can implement those easily. :-)