Site security is not being implemented on the constituent recognition processes. Users from any site can launch processes from any other site as long as they have the appropriate permissions to access this application area.
This has been resolved in Service Pack 17. Please download and install the latest Service Pack or Hot Fix which contains all fixes from previous patches.
Steps to Duplicate
Go to 'Constituents' functional area. Go to 'Constituent Recognition Processes'. Run a process created for another site.