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Fencer Intel
medium 5.3

CVE-2026-84429 json

Potential denial-of-service vulnerability in HTTP header parsing

published last mo. modified last mo. also EUVD-2026-93417

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

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 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.

Patch / fix

  • djangoproject Django 5.2.18, 6.0.9, 6.1.2
  • python-django Debian 14 3:5.2.18-1

debian advisories DEBIAN-CVE-2026-84429

  • python-Django SLE Module for Package Hub 15 SP7 4.2.11-150600.3.68.1

suse advisories SUSE-SU-2026:4626-1

  • python-Django openSUSE Leap 16.0 5.2.4-bp160.12.1
  • python-Django openSUSE Tumbleweed 6.1.2-1.1
  • python-Django5 openSUSE Tumbleweed 5.2.18-1.1
  • python-Django4 openSUSE Tumbleweed 4.2.30-6.1

opensuse advisories openSUSE-SU-2026:22196-1openSUSE-SU-2026:12103-1openSUSE-SU-2026:12095-1openSUSE-SU-2026:12086-1

  • py3-django Alpine 3.24 5.2.18-r0

alpine advisories ALPINE-CVE-2026-84429

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-84429 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-84429 updated cvss 5.3

django: Denial of service via quadratic parsing complexity in parse_header_parameters()

  • Red Hat Ansible Automation Platform 2 python-django 4.2.24-1.el9ap, python3x-django 4.2.24-1.el8ap, python3.11-django 4.2.27-2.el9ap, python3.12-django 5.2.17-1.el9ap, automation-controller 4.7.17-1.el9ap, ansible-automation-platform-24/hub-rhel8, +25 more
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat Discovery 2 discovery/discovery-server-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenStack Platform 13 (Queens) python2-django, python-django 4.2.24-1.el9ap, python-django-bash-completion Red Hat OpenStack Platform 16.2 python-django20, python3-django20, rhosp-rhel8/openstack-horizon, python-django20-bash-completion Red Hat OpenStack Platform 17.1 python3-django, python-django 4.2.24-1.el9ap, rhosp-rhel9/openstack-horizon
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenStack Platform 18.0 python-django 4.2.24-1.el9ap, rhoso/openstack-horizon-rhel9 Red Hat Satellite 6 python-django, python2-django, python-django 4.2.24-1.el9ap, python-django-bash-completion, python3.12-django 5.2.17-1.el9ap, satellite/iop-advisor-backend-rhel9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Update Infrastructure 4 for Cloud Providers python-django 4.2.24-1.el9ap
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Update Infrastructure 5 rhui5/rhua-rhel9, rhui5/rhua-tp-rhel9 Red Hat Self-service automation portal 2 ansible-automation-platform/bootc-automation-portal-rhel9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • djangoproject Django

Classification

Weakness
  • CWE-407 Inefficient Algorithmic Complexity
Technology feeds

References

Sources

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