CVE-2026-3902 PUBLISHED

ASGI header spoofing via underscore/hyphen conflation

Assigner: DSF
Reserved: 10.03.2026 Published: 07.04.2026 Updated: 07.04.2026

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.

Product Status

Vendor djangoproject
Product Django
Versions Default: unaffected
  • affected from 6.0 to 6.0.4 (excl.)
  • Version 6.0.4 is unaffected
  • affected from 5.2 to 5.2.13 (excl.)
  • Version 5.2.13 is unaffected
  • affected from 4.2 to 4.2.30 (excl.)
  • Version 4.2.30 is unaffected

Credits

  • Tarek Nakkouch reporter
  • Jacob Walls remediation developer
  • Jacob Walls coordinator

References

Problem Types

  • CWE-290: Authentication Bypass by Spoofing CWE

Impacts

  • CAPEC-151: Identity Spoofing