# Django 5.2.9 - dokumentacja

# Django 4.1.12 release notes

October 4, 2023

Django 4.1.12 fixes a security issue with severity „moderate” in 4.1.11.

## CVE-2023-43665: Denial-of-service possibility in `django.utils.text.Truncator`

Following the fix for CVE 2019-14232, the regular expressions used in the implementation of `django.utils.text.Truncator`’s `chars()` and `words()` methods (with `html=True`) were revised and improved. However, these regular expressions still exhibited linear backtracking complexity, so when given a very long, potentially malformed HTML input, the evaluation would still be slow, leading to a potential denial of service vulnerability.

The `chars()` and `words()` methods are used to implement the `truncatechars_html` and `truncatewords_html` template filters, which were thus also vulnerable.

The input processed by `Truncator`, when operating in HTML mode, has been limited to the first five million characters in order to avoid potential performance and memory issues.