CVE-2026-3902

CVE-2026-3902: ASGI header spoofing via underscore/hyphen conflation

Vendor Djangoproject
Product Django
Weakness CWE-290
Published April 7, 2026
Last update April 7, 2026

CVSS base score

What the vulnerability does

01Description

An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.13, and 4.2 before 4.2.30. `ASGIRequest` allows a remote attacker to spoof headers by exploiting an ambiguous mapping of two header variants (with hyphens or with underscores) to a single version with underscores. Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected. Django would like to thank Tarek Nakkouch for reporting this issue.

Key dates

02Disclosure timeline

April 7, 2026 CVE published
April 7, 2026 Record updated