# Django 5.2.7 documentation

# 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+, `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 `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 `select_for_update()`. When using related fields pointing to a proxy model in the `of` argument, the corresponding model was not locked (#31866).

- Fixed a data loss possibility, following a regression in Django 2.0, when copying model instances with a cached fields value (#31863).