USN-4975-1 fixed a vulnerability in Django. This update provides the corresponding update for Ubuntu 16.04 ESM.
Original advisory details:
Rasmus Lerchedahl Petersen and Rasmus Wriedt Larsen discovered that Django incorrectly handled path sanitation in admindocs. A remote attacker could possibly use this issue to determine the existence of arbitrary files and in certain configurations obtain their contents. (CVE-2021-33203)
{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python-django",
            "binary_version": "1.8.7-1ubuntu5.15+esm3"
        },
        {
            "binary_name": "python-django-common",
            "binary_version": "1.8.7-1ubuntu5.15+esm3"
        },
        {
            "binary_name": "python3-django",
            "binary_version": "1.8.7-1ubuntu5.15+esm3"
        }
    ]
}