Security issues were identified and fixed in firefox 3.5.x: The nsObserverList::FillObserverArray function in xpcom/ds/nsObserverList.cpp in Mozilla Firefox before 3.5.7 allows remote attackers to cause a denial of service via a crafted web site that triggers memory consumption and an accompanying Low Memory alert dialog, and also triggers attempted removal of an observer from an empty observers array . Additionally, some packages which require so, have been rebuilt and are being provided as updates.