django/docs/releases/2.2.16.txt

===========================
Django 2.2.16 release notes
===========================

*September 1, 2020*

Django 2.2.16 fixes two security issues and two data loss bugs in 2.2.15.

CVE-2020-24583: Incorrect permissions on intermediate-level directories on Python 3.7+
======================================================================================

On Python 3.7+, :setting:`FILE_UPLOAD_DIRECTORY_PERMISSIONS` mode was not
applied to intermediate-level directories created in the process of uploading
files and to intermediate-level collected static directories when using the
:djadmin:`collectstatic` management command.

You should review and manually fix permissions on existing intermediate-level
directories.

CVE-2020-24584: Permission escalation in intermediate-level directories of the file system cache on Python 3.7+
===============================================================================================================

On Python 3.7+, the intermediate-level directories of the file system cache had
the system's standard umask rather than ``0o077`` (no group or others
permissions).

Bugfixes
========

* Fixed a data loss possibility in the
  :meth:`~django.db.models.query.QuerySet.select_for_update()`. When using
  related fields pointing to a proxy model in the ``of`` argument, the
  corresponding model was not locked (:ticket:`31866`).

* Fixed a data loss possibility, following a regression in Django 2.0, when
  copying model instances with a cached fields value (:ticket:`31863`).