The extension implementation in Google Chrome before 17.0.963.46 does not properly handle sandboxed origins, which might allow remote attackers to bypass the Same Origin Policy via a crafted extension.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14906
http://googlechromereleases.blogspot.com/2012/02/stable-channel-update.html