In Django 3.2 before 3.2.20, 4 before 4.1.10, and 4.2 before 4.2.3, EmailValidator and URLValidator are subject to a potential ReDoS (regular expression denial of service) attack via a very large number of domain name labels of emails and URLs.
https://www.djangoproject.com/weblog/2023/jul/03/security-releases/
https://www.debian.org/security/2023/dsa-5465
https://lists.debian.org/debian-lts-announce/2023/07/msg00022.html