CVE-2026-87975

Privilege abuse in model formsets with editable primary keys

Published Oct 6, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
An issue was discovered in Django 6.1 before 6.1.2, 6.0 before 6.0.9, and 5.2 before 5.2.18.
`django.forms.models.BaseModelFormSet.save_existing_objects()` used the presence of a primary key on a submitted form's instance as evidence that the instance belonged to the formset's limiting queryset. An object outside that queryset is represented by a newly constructed instance whose primary key can still be populated from submitted data when the model's primary key is a field accepted by the form, such as 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. This allows an authenticated user permitted to submit such a formset to delete rows outside the limiting queryset, without any permission on the targeted object, via forged management-form data marking an out-of-queryset object for deletion. Models using the default AutoField primary key are not affected.
Earlier, unsupported Django series (such as 5.1.x, 5.0.x, and 4.2.x) were not evaluated and may also be affected.
Django would like to thank Seonggwon Yoon for reporting this issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4843-1 python-django security update
History
Type Values Removed Values Added
First Time appeared Djangoproject
Djangoproject django
Vendors & Products Djangoproject
Djangoproject django
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description An issue was discovered in Django 6.1 before 6.1.2, 6.0 before 6.0.9, and 5.2 before 5.2.18. `django.forms.models.BaseModelFormSet.save_existing_objects()` used the presence of a primary key on a submitted form's instance as evidence that the instance belonged to the formset's limiting queryset. An object outside that queryset is represented by a newly constructed instance whose primary key can still be populated from submitted data when the model's primary key is a field accepted by the form, such as 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. This allows an authenticated user permitted to submit such a formset to delete rows outside the limiting queryset, without any permission on the targeted object, via forged management-form data marking an out-of-queryset object for deletion. Models using the default AutoField primary key are not affected. Earlier, unsupported Django series (such as 5.1.x, 5.0.x, and 4.2.x) were not evaluated and may also be affected. Django would like to thank Seonggwon Yoon for reporting this issue.
Title Privilege abuse in model formsets with editable primary keys
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
DSF
Published
Updated
Oct 6, 2026, 1:53 PM
Reserved
Sep 9, 2026, 6:18 PM
Status
Deferred
Published
Oct 6, 2026, 2:17 PM
Modified
Oct 6, 2026, 2:17 PM
Severity
Moderate
Public date
Oct 6, 2026, 2:20 PM