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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-mvfq-ggxm-9mc5 Django vulnerable to ASGI header spoofing via underscore/hyphen conflation
Ubuntu USN Ubuntu USN USN-8154-1 Django vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 08 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Djangoproject
Djangoproject django
Vendors & Products Djangoproject
Djangoproject django

Wed, 08 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-444
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 07 Apr 2026 18:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 07 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Description 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.
Title ASGI header spoofing via underscore/hyphen conflation
Weaknesses CWE-290
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: DSF

Published:

Updated: 2026-04-07T16:14:07.198Z

Reserved: 2026-03-10T18:33:26.472Z

Link: CVE-2026-3902

cve-icon Vulnrichment

Updated: 2026-04-07T16:13:58.332Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-07T15:17:46.353

Modified: 2026-04-08T21:27:00.663

Link: CVE-2026-3902

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-07T14:22:07Z

Links: CVE-2026-3902 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-08T19:49:06Z

Weaknesses