Inefficient Algorithmic Complexity in Django - CVE-2026-84429
Published: October 7, 2026
Vulnerability identifier: #VU153883
CSH Severity: Medium
CVSS v4: 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]
CVE-ID: CVE-2026-84429
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
nThe vulnerability exists due to quadratic time complexity in django.utils.http.parse_header_parameters() when parsing header values containing many separators inside a quoted parameter. A remote attacker can send a specially crafted request containing such values in Accept or Content-Type headers to cause a denial of service.
nUnauthenticated requests can reach the parser through content negotiation performed by HttpRequest.accepts(). The per-call length limit does not bound the combined size of repeated headers.
Affected software
Django
How to mitigate CVE-2026-84429
Install security update from vendor's website.
Django - addressed in versions 5.2.18, 6.0.9, 6.1.2