Django security releases issued: 4.1.6, 4.0.9, and 3.2.17

Posted by Carlton Gibson & Mariusz Felisiak on February 1, 2023

In accordance with our security release policy, the Django team is issuing Django 4.1.6, Django 4.0.9, and Django 3.2.17. These releases addresses the security issue detailed below. We encourage all users of Django to upgrade as soon as possible.

CVE-2023-23969: Potential denial-of-service via Accept-Language headers

The parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if large header values are sent.

In order to avoid this vulnerability, the Accept-Language header is now parsed up to a maximum length.

Thanks to Mithril for the report.

This issue has severity "moderate" according to the Django security policy.

Affected supported versions

  • Django main branch
  • Django 4.2 (currently at pre-release alpha status)
  • Django 4.1
  • Django 4.0
  • Django 3.2


Patches to resolve the issue have been applied to Django's main branch and the 4.2, 4.1, 4.0, and 3.2 release branches. The patches may be obtained from the following changesets:

The following releases have been issued:

The PGP key ID used for this release is Mariusz Felisiak: 2EF56372BA48CD1B.

General notes regarding security reporting

As always, we ask that potential security issues be reported via private email to, and not via Django's Trac instance or the django-developers list. Please see our security policies for further information.

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