The XML libraries for Python 3.4 3.3 3.2 3.1 2.7 and 2.6 as used in OpenStack Keystone Essex Folsom and Grizzly; Compute (Nova) Essex and Folsom; Cinder Folsom; Django; and possibly other products allow remote attackers to cause a denial of service (resource consumption and crash) via an XML Entity Expansion (XEE) attack.