CVE-2026-3902

Summary

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.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://docs.djangoproject.com/en/dev/releases/security/ ↗

Additional information

• NVD record
• https://docs.djangoproject.com/en/dev/releases/security/Patch
• https://www.djangoproject.com/weblog/2026/apr/07/security-releases/Patch
• https://groups.google.com/g/django-announce