Firefox before 1.0 and Mozilla before 1.7.5 allow remote attackers to load local files via links "with a custom getter and toString method" that are middle-clicked by the user to be opened in a new tab.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10756
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A100057
https://exchange.xforce.ibmcloud.com/vulnerabilities/19168
https://bugzilla.mozilla.org/show_bug.cgi?id=249332
http://www.securityfocus.com/bid/12407
http://www.redhat.com/support/errata/RHSA-2005-335.html