===========================
Django 4.2.21 release notes
===========================

*May 7, 2025*

Django 4.2.21 fixes a security issue with severity "moderate", a data loss bug,
and a regression in 4.2.20.

This release was built using an upgraded :pypi:`setuptools`, producing
filenames compliant with :pep:`491` and :pep:`625` and thus addressing a PyPI
warning about non-compliant distribution filenames. This change only affects
the Django packaging process and does not impact Django's behavior.

CVE-2025-32873: Denial-of-service possibility in ``strip_tags()``
=================================================================

:func:`~django.utils.html.strip_tags` would be slow to evaluate certain inputs
containing large sequences of incomplete HTML tags. This function is used to
implement the :tfilter:`striptags` template filter, which was thus also
vulnerable.

:func:`~django.utils.html.strip_tags` now raises a :exc:`.SuspiciousOperation`
exception if it encounters an unusually large number of unclosed opening tags.

Bugfixes
========

* Fixed a data corruption possibility in ``file_move_safe()`` when
  ``allow_overwrite=True``, where leftover content from a previously larger
  file could remain after overwriting with a smaller one due to lack of
  truncation (:ticket:`36298`).

* Fixed a regression in Django 4.2.20, introduced when fixing
  :cve:`2025-26699`, where the :tfilter:`wordwrap` template filter did not
  preserve empty lines between paragraphs after wrapping text
  (:ticket:`36341`).
