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CVE-2026-3902

ASGI header spoofing via underscore/hyphen conflation

Published: Apr 7, 2026Updated: Apr 13, 2026 Sources: CVE List NVD BDUCWE-290
NVD MITRE
7.5CVSSHIGH
EPSS Score
0.4%
Top 65.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:HIntegrity
High
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-290

Affected Products

djangodjangoprojectOSS Libraries
DjangodjangoprojectOSS Libraries
UbuntuCanonical Ltd.
On-premOS
Operating Systems / linux-distro
РЕД ОСООО «Ред Софт»
On-premOS
Operating Systems / linux-distro
Red Hat SatelliteRed Hat Inc.
On-prem
Operating Systems
djangoprojectoss-projectOSS Librariesaka django
canonical ltd.commercialGBOperating Systemsaka canonical
ооо «ред софт»commercialRUOperating Systemsaka red soft
red hat inc.commercialUSOperating Systemsaka red hat
and 3 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://docs.djangoproject.com/en/dev/releases/security/
docs.djangoproject.com
https://groups.google.com/g/django-announce
groups.google.com
https://www.djangoproject.com/weblog/2026/apr/07/security-releases/
djangoproject.com
and 6 more references View all →

Timeline

Published
Apr 7, 2026
Last Updated
Apr 13, 2026

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