django/docs/releases/1.8.19.txt

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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.