GHSA-r28v-mw67-m5p9 Django denial-of-service possibility in urlize and urlizetrunc template filters

• PyPI Django: >= 2.0a1, < 2.0.3 → fixed in 2.0.3 • PyPI Django: >= 1.11a1, < 1.11.11 → fixed in 1.11.11 • PyPI Django: >= 1.8a1, < 1.8.19 → fixed in 1.8.19

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. The `django.utils.html.urlize()` function was extremely slow to evaluate certain inputs due to catastrophic backtracking vulnerabilities in two regular expressions (only one regular expression for Django 1.8.x). The `urlize()` function is used to implement the urlize and urlizetrunc template filters, which were thus vulnerable.