GitHub Advisoryadvisory · PyPI
GHSA-mvfq-ggxm-9mc5 Django vulnerable to ASGI header spoofing via underscore/hyphen conflation
HIGH
Official page ↗
- Aliases
- CVE-2026-3902
- Ecosystem
- PyPI
- Packages
- Django
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weaknesses
- CWE-290
- Reviewed
- 2026-04-08
Affected packages
• PyPI Django: >= 6.0, < 6.0.4 → fixed in 6.0.4
• PyPI Django: >= 5.2, < 5.2.13 → fixed in 5.2.13
• PyPI Django: >= 4.2, < 4.2.30 → fixed in 4.2.30
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.
Related
Alias · CVE (1)
- CVE-2026-3902 An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.13, and 4.2 before 4.2.30. vulnerability
Weakness · CWE (1)
- CWE-290 Authentication Bypass by Spoofing weakness
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-3902 advisory
- https://docs.djangoproject.com/en/dev/releases/security web
- https://github.com/django/django package
- https://github.com/pypa/advisory-database/tree/main/vulns/django/PYSEC-2026-51.yaml web
- https://groups.google.com/g/django-announce web
- https://www.djangoproject.com/weblog/2026/apr/07/security-releases web