Use-after-free vulnerability in the Notifications presenter in Google Chrome before 6.0.472.53 allows attackers to cause a denial of service or possibly have unspecified other impact via unknown vectors.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11987
http://googlechromereleases.blogspot.com/2010/09/stable-and-beta-channel-updates.html