USN-2915-1 fixed vulnerabilities in Django. The upstream fix for CVE-2016-2512 introduced a regression for certain applications. This update fixes the problem by applying the complete upstream regression fix.
Original advisory details:
Mark Striemer discovered that Django incorrectly handled user-supplied redirect URLs containing basic authentication credentials. A remote attacker could possibly use this issue to perform a cross-site scripting attack or a malicious redirect. (CVE-2016-2512)
Sjoerd Job Postmus discovered that Django incorrectly handled timing when doing password hashing operations. A remote attacker could possibly use this issue to perform user enumeration. (CVE-2016-2513)