Django before 1.4.21, 1.5.x through 1.6.x, 1.7.x before 1.7.9, and 1.8.x before 1.8.3 uses an incorrect regular expression, which allows remote attackers to inject arbitrary headers and conduct HTTP response splitting attacks via a newline character in an (1) email message to the EmailValidator, a (2) URL to the URLValidator, or unspecified vectors to the (3) validate_ipv4_address or (4) validate_slug validator.

The session backends in Django before 1.4.21, 1.5.x through 1.6.x, 1.7.x before 1.7.9, and 1.8.x before 1.8.3 allows remote attackers to cause a denial of service (session store consumption) via multiple requests with unique session keys.

The utils.http.is_safe_url function in Django before 1.4.20, 1.5.x, 1.6.x before 1.6.11, 1.7.x before 1.7.7, and 1.8.x before 1.8c1 does not properly validate URLs, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a control character in a URL, as demonstrated by a \x08javascript: URL.