Way to reproduce :
In the admin interface > content/urlwildcards, create a redirection from "redirect/to" to "redirect/To"
Then go to redirect/to, you will then enter in an infinite redirection loop.

Expected behavior : you should get redirected to "redirect/To" only once, but instead, the system matches the new URL (redirect/To) with the rule (redirect/to) again and again.

Note: Not sure since when this feature is not working since I'm upgrading from 4.0.1...