Launchpad.net

CVE 2011-4136

django.contrib.sessions in Django before 1.2.7 and 1.3.x before 1.3.1, when session data is stored in the cache, uses the root namespace for both session identifiers and application-data keys, which allows remote attackers to modify a session by triggering use of a key that is equal to that session's identifier.

See the CVE page on Mitre.org for more details.