# Django 3.0.15.dev documentation

# Django 1.8.19 release notes

March 6, 2018

Django 1.8.19 fixes two security issues in 1.18.18.

## CVE-2018-7536: Denial-of-service possibility in `urlize` and `urlizetrunc` template filters

The `django.utils.html.urlize()` function was extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The `urlize()` function is used to implement the `urlize` and `urlizetrunc` template filters, which were thus vulnerable.

The problematic regular expression is replaced with parsing logic that behaves similarly.

## CVE-2018-7537: Denial-of-service possibility in `truncatechars_html` and `truncatewords_html` template filters

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.

The backtracking problem in the regular expression is fixed.