# Django 4.2.9.dev20231204082947 - dokumentacja

# Django 4.1.13 release notes

November 1, 2023

Django 4.1.13 fixes a security issue with severity „moderate” in 4.1.12.

## CVE-2023-46695: Potential denial of service vulnerability in `UsernameField` on Windows

The `NFKC normalization` is slow on Windows. As a consequence, `django.contrib.auth.forms.UsernameField` was subject to a potential denial of service attack via certain inputs with a very large number of Unicode characters.

In order to avoid the vulnerability, invalid values longer than `UsernameField.max_length` are no longer normalized, since they cannot pass validation anyway.