Last modified: 2013-09-06 09:32:22 UTC
Set the title to something like "<big><big><big><big>test" and you end up with https://test.wikipedia.org/w/index.php?title=Campaign:wlm-pl&oldid=179050 (Sitenote, there's a bug where <'s get changed into random unicode characters. filing that separately.)
sidenote*
Perhaps should pass things through tidy before outputting them. These are already passed through the wikitext parser, so should not cause XSS issues. Or perhaps, if people want to fuck up the page, let them?