The form library in Django 1.3.x before 1.3.6, 1.4.x before 1.4.4, and 1.5 before release candidate 2 allows remote attackers to bypass intended resource limits for formsets and cause a denial of service (memory consumption) or trigger server errors via a modified max_num parameter.
The django.http.HttpRequest.get_host function in Django 1.3.x before 1.3.4 and 1.4.x before 1.4.2 allows remote attackers to generate and display arbitrary URLs via crafted username and password Host header values.