Django Incorrect Regular Expression Vulnerability - CVE-2018-7537

An issue was discovered in Django 2.0 before 2.0.3 1.11 before 1.11.11 and 1.8 before 1.8.19. If django.utils.text.Truncator39s chars() and words() methods were passed the htmlTrue 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.