Input in the Feed Builder is not properly handled.
Insert:
"><<script>alert('Gotcha!')</script>
as the feed name (title) and you get url like this:
http://confluence.atlassian.com/dashboard/doconfigurerssfeed.action?types=page&types=blogpost&types=mail&types=comment&types=attachment&sort=modified&showContent=true&showDiff=true&spaces=conf_global&labelString=&rssType=atom&maxResults=10&timeSpan=5&publicFeed=true&title=%22%3E%3C%3Cscript%3Ealert%28%27Gotcha%21%27%29%3C%2Fscript%3E
Suggested fix: Escape output of title in
<link rel="alternate" type="application/atom+xml" title="" href=""/>
/dashboard/doconfigurerssfeed.action