Use-after-free vulnerability in Google Chrome before 28.0.1500.95 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to deleting the registration of a MutationObserver object.
https://src.chromium.org/viewvc/blink?revision=154264&view=revision
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17525
https://code.google.com/p/chromium/issues/detail?id=260165
http://www.debian.org/security/2013/dsa-2732
http://googlechromereleases.blogspot.com/2013/07/stable-channel-update_30.html