In Django 3.2 before 3.2.22, 4.1 before 4.1.12, and 4.2 before 4.2.6, the django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.
https://www.djangoproject.com/weblog/2023/oct/04/security-releases/
https://security.netapp.com/advisory/ntap-20231221-0001/
https://groups.google.com/forum/#%21forum/django-announce