Django security releases issued: 6.1.2, 6.0.9, and 5.2.18

In accordance with our security release policy, the Django team is issuing releases for Django 6.1.2, Django 6.0.9, and Django 5.2.18. These releases address the security issues detailed below. We encourage all users of Django to upgrade as soon as possible.

CVE-2026-77050: Potential denial-of-service vulnerability in get_supported_language_variant()

django.utils.translation.get_supported_language_variant() was subject to a potential denial-of-service attack when processing many distinct, very long language codes. Language codes were used as keys in an in-memory cache before their length was limited, potentially consuming excessive process memory.

To mitigate this vulnerability, language codes longer than 500 characters are now rejected or truncated before the cached lookup.

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

Thanks to Gleb Lizunov for the report.

CVE-2026-84429: Potential denial-of-service vulnerability in HTTP header parsing

django.utils.http.parse_header_parameters() was subject to a potential denial-of-service attack due to quadratic time complexity when parsing a value with many separators inside a quoted parameter. An unauthenticated request could reach this parsing through headers such as Accept or Content-Type, for instance via the content negotiation performed by HttpRequest.accepts(). The per-call length limit does not bound the combined size of repeated headers.

The undocumented django.utils.http.parse_header_parameters() function now uses Python's email.message.Message for parsing. As a result, parsing of some malformed or unusual header values may differ, for example, RFC 2231 values with a missing encoding are now decoded.

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

Thanks to Jisung Chae for the report.

CVE-2026-87890: Potential request forgery via spatial lookup byte values

Spatial lookups accepted raster values provided as bytes without requiring them to be explicitly wrapped in django.contrib.gis.gdal.GDALRaster. Although these values were opened through GDAL's in-memory virtual filesystem, they could contain a VRT document referencing an external raster source. This could cause GDAL to issue network requests as the Django process user while preparing the lookup.

This issue could be exploited by applications that passed attacker-controlled bytes directly to a spatial lookup. It was overlooked in the fix for CVE-2026-15307.

To mitigate this issue, raster values provided as bytes must now be wrapped in GDALRaster before being used in spatial lookups. Byte values representing valid hexadecimal geometries remain accepted.

This is a backward incompatible change. As a reminder, all untrusted user input should be validated before use.

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

Thanks to sicksec for the report.

CVE-2026-87975: Privilege abuse in model formsets with editable primary keys

Model formsets incorrectly allowed forged POST data to either delete instances outside the limiting queryset or create instances via edit-only formsets when the model's primary key could be set through the form, such as with: a OneToOneField (or parent link used as the primary key of an inline formset's model), or a natural or UUID primary key included in the form's fields. Models using the default BigAutoField primary key were not affected.

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

Thanks to Seonggwon Yoon for the report.

Affected supported versions

• Django main
• Django 6.1
• Django 6.0
• Django 5.2

Resolution

Patches to resolve the issue have been applied to Django's main, 6.1, 6.0, and 5.2 branches. The patches may be obtained from the following changesets.

CVE-2026-77050: Potential denial-of-service vulnerability in get_supported_language_variant()

• On the main branch
• On the 6.1 branch
• On the 6.0 branch
• On the 5.2 branch

CVE-2026-84429: Potential denial-of-service vulnerability in HTTP header parsing

• On the main branch
• On the 6.1 branch
• On the 6.0 branch
• On the 5.2 branch

CVE-2026-87890: Potential request forgery via spatial lookup byte values

• On the main branch
• On the 6.1 branch
• On the 6.0 branch
• On the 5.2 branch

CVE-2026-87975: Privilege abuse in model formsets with editable primary keys

• On the main branch
• On the 6.1 branch
• On the 6.0 branch
• On the 5.2 branch

The following releases have been issued

• Django 6.1.2 (tarball | checksums)
• Django 6.0.9 (tarball | checksums)
• Django 5.2.18 (tarball | checksums)

The PGP key ID used for this release is Sarah Boyce: 3955B19851EA96EF

General notes regarding security reporting

As always, we ask that potential security issues be reported via private email to security@djangoproject.com, and not via Django's Trac instance, nor via the Django Forum. Please see our security policies for further information.