5.3Medium

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

djangoproject Django Published: (1 month ago)

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.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.

Weakness (CWE): CWE-407

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

VendorProductVersions
djangoproject Django 6.1 – < 6.1.2, fixed 6.1.2, 6.0 – < 6.0.9, fixed 6.0.9, 5.2 – < 5.2.18, fixed 5.2.18

References and patches