Django up to 4.2.29/5.2.12/6.0.3 ASGIRequest authentication spoofing

Summaryinfo

A vulnerability has been found in Django up to 4.2.29/5.2.12/6.0.3 and classified as critical. This impacts an unknown function of the component ASGIRequest. This manipulation causes authentication spoofing. This vulnerability is handled as CVE-2026-3902. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Django up to 4.2.29/5.2.12/6.0.3. Affected by this vulnerability is an unknown part of the component ASGIRequest. The manipulation with an unknown input leads to a authentication spoofing vulnerability. The CWE definition for the vulnerability is CWE-290. This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at docs.djangoproject.com. This vulnerability is known as CVE-2026-3902 since 03/10/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/09/2026).

The vulnerability scanner Nessus provides a plugin with the ID 305750 (Python Library Django 4.2.x < 4.2.30 / 5.2.x < 5.2.13 / 6.0.x < 6.0.4 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.2.30, 5.2.13 or 6.0.4 eliminates this vulnerability. The upgrade is hosted for download at docs.djangoproject.com.

The vulnerability is also documented in the databases at Tenable (305750) and CERT Bund (WID-SEC-2026-1002). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Ubuntu Linux
• Open Source Django

Productinfo

Type

• Content Management System

Name

• Django

Version

• 4.2.0
• 4.2.1
• 4.2.2
• 4.2.3
• 4.2.4
• 4.2.5
• 4.2.6
• 4.2.7
• 4.2.8
• 4.2.9
• 4.2.10
• 4.2.11
• 4.2.12
• 4.2.13
• 4.2.14
• 4.2.15
• 4.2.16
• 4.2.17
• 4.2.18
• 4.2.19
• 4.2.20
• 4.2.21
• 4.2.22
• 4.2.23
• 4.2.24
• 4.2.25
• 4.2.26
• 4.2.27
• 4.2.28
• 4.2.29
• 5.2.0
• 5.2.1
• 5.2.2
• 5.2.3
• 5.2.4
• 5.2.5
• 5.2.6
• 5.2.7
• 5.2.8
• 5.2.9
• 5.2.10
• 5.2.11
• 5.2.12
• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3

License

• open-source

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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