An issue was discovered in Django 1.11.x before 1.11.23, 2.1.x before 2.1.11, and 2.2.x before 2.2.4. If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.
https://www.djangoproject.com/weblog/2019/aug/01/security-releases/
https://www.debian.org/security/2019/dsa-4498
https://security.netapp.com/advisory/ntap-20190828-0002/
https://security.gentoo.org/glsa/202004-17
https://seclists.org/bugtraq/2019/Aug/15
https://groups.google.com/forum/#%21topic/django-announce/jIoju2-KLDs
https://docs.djangoproject.com/en/dev/releases/security/
http://www.openwall.com/lists/oss-security/2024/03/04/1
http://www.openwall.com/lists/oss-security/2023/10/04/6
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00006.html