Cross-site scripting (XSS) vulnerability in Google Toolbar 2.0.114.1 allows remote attackers to inject arbitrary web script via about.html in the About section. NOTE: some followup posts suggest that the demonstration code's use of the res:// protocol does not cross privilege boundaries, since it is not allowed in the Internet Zone. Thus this might not be a vulnerability.

The Google toolbar 1.1.58 and earlier allows remote web sites to monitor a user's input into the toolbar via an "onkeydown" event handler.