Flaw first flagged by a teenage blogger could allow the execution of script code, possibly resulting in account hijacks.
http://news.com.com/Google+fixes+minor+Gmail+flaw/2100-1002_3-6045416.html?part=rss&tag=6045416&subj=news
http://news.com.com/Google+fixes+minor+Gmail+flaw/2100-1002_3-6045416.html?part=rss&tag=6045416&subj=news