A Bugzilla Security Advisory reports:
Sometimes the information put into the <h1> and <h2> tags in Bugzilla was not properly escaped, leading to a possible XSS vulnerability. Bugzilla administrators were allowed to put raw, unfiltered HTML into many fields in Bugzilla, leading to a possible XSS vulnerability. Now, the HTML allowed in those fields is limited. attachment.cgi could leak the names of private attachments The "deadline" field was visible in the XML format of a bug, even to users who were not a member of the "timetrackinggroup." A malicious user could pass a URL to an admin, and make the admin delete or change something that he had not intended to delete or change. It is possible to inject arbitrary HTML into the showdependencygraph.cgi page, allowing for a cross-site scripting attack.