An issue was discovered in Django 5.1 before 5.1.8 and 5.0 before 5.0.14. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.views.LoginView, django.contrib.auth.views.LogoutView, and django.views.i18n.set_language are subject to a potential denial-of-service attack via certain inputs with a very large number of Unicode characters.
An issue was discovered in Django 5.1 before 5.1.7, 5.0 before 5.0.13, and 4.2 before 4.2.20. The django.utils.text.wrap() method and wordwrap template filter are subject to a potential denial-of-service attack when used with very long strings.
An issue was discovered in Django 5.1 before 5.1.5, 5.0 before 5.0.11, and 4.2 before 4.2.18. Lack of upper-bound limit enforcement in strings passed when performing IPv6 validation could lead to a potential denial-of-service attack. The undocumented and private functions clean_ipv6_address and is_valid_ipv6_address are vulnerable, as is the django.forms.GenericIPAddressField form field. (The django.db.models.GenericIPAddressField model field is not affected.)