parent / child processes

Process A creates another process B. Process A then dies, but process B still has the PID of process A marked as its parent process. Later on, a process C starts and is randomly assigned the PID that process A was originally assigned.

Are there any security or other implications of this happening?

In Windows, child processes maintain a link back to the parent process. If the parent dies, this information isn't updated, however this isn't a problem since nothing relies on that information being present.