CVE-2026-3902
highpriority · track · 0EPSS 0.004 · 38 %ileDEEURUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (38)
Products and version ranges known to be affected.
advisories (4)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-1002Django: Mehrere SchwachstellenDeutsch2026-04-07csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Django ausnutzen, um einen Denial-of-Service-Zustand herbeizuführen, Daten zu manipulieren oder Sicherheitsmaßnahmen zu umgehen.
- GHSA-mvfq-ggxm-9mc5Django vulnerable to ASGI header spoofing via underscore/hyphen conflation2026-04-07ghsa · osvUS
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.
- BIT-django-2026-3902ASGI header spoofing via underscore/hyphen conflation2026-04-16vendor · osvUS
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.
- PYSEC-2026-512026-04-07vendor · osvUS
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.
also known as (8)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://docs.djangoproject.com/en/dev/releases/security/cnnvd
- https://groups.google.com/g/django-announcecnnvd
- https://vigilance.fr/vulnerability/Django-multiple-vulnerabilities-dated-08-04-2026-50383cnnvd
- https://www.djangoproject.com/weblog/2026/apr/07/security-releases/cnnvd
- https://docs.djangoproject.com/en/dev/releases/security/enisa_euvd
- https://groups.google.com/g/django-announceenisa_euvd
- https://www.djangoproject.com/weblog/2026/apr/07/security-releases/enisa_euvd
- https://docs.djangoproject.com/en/dev/releases/security/PatchVendor Advisorynvd
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