---
id: CVE-2026-84429
title: >-
  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.utils.http.parse_header_parameters()` was subject to a potential
  denial-of-service attack due to quadratic time complexity when parsing …
summary: >-
  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.utils.http.parse_header_parameters()` was subject to a potential
  denial-of-service attack due to quadratic time complexity when parsing …
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-407
vendor: djangoproject
product: django
affected:
  - django >= 6.1 < 6.1.2
  - django >= 6.0 < 6.0.9
  - django >= 5.2 < 5.2.18
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T15:17:19.860'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84429'
references:
  - url: 'https://docs.djangoproject.com/en/dev/releases/security/'
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: >-
      https://github.com/django/django/commit/3d8f121695c21234aff3071de0d38b6bd38c3f52
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: >-
      https://github.com/django/django/commit/6ecd66e09a383be004a78a3a738ea9727ff07b0e
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: >-
      https://github.com/django/django/commit/7ff7fcc0508864a4bc39693128ace38b1e95a890
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: >-
      https://github.com/django/django/commit/de56deeabd4c48dfb5193f0001469d80102fb367
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: 'https://groups.google.com/g/django-announce'
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
  - url: 'https://www.djangoproject.com/weblog/2026/oct/06/security-releases/'
    label: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-06T14:12:40.577982Z'
ingestedAt: '2026-10-06T14:00:19.152Z'
---

## Overview

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.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.
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 Jisung Chae for reporting this issue.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.