Vim is an open source, command line text editor. Prior to 9.2.0736, the PHP omni-completion script in runtime/autoload/phpcomplete.vim interpolates a class or trait name, taken from the contents of the edited buffer, into a search() pattern that is run via win_execute() without escaping. A name containing a single quote can terminate the search() string argument early, and because the bar is honored as an Ex command separator, the remainder of the name is run as Ex commands; via the :! command this allows arbitrary operating-system command execution when a victim opens a crafted PHP file and invokes omni-completion. This issue is fixed in version 9.2.0736.