In Django 2.2 before 2.2.20, 3.0 before 3.0.14, and 3.1 before 3.1.8, MultiPartParser allowed directory traversal via uploaded files with suitably crafted file names. Built-in upload handlers were not affected by this vulnerability.
https://www.djangoproject.com/weblog/2021/apr/06/security-releases/
https://security.netapp.com/advisory/ntap-20210528-0001/
https://lists.debian.org/debian-lts-announce/2021/04/msg00008.html