CVE-2026-3902: ASGI header spoofing via underscore/hyphen conflation

Published Apr 7, 2026
·
Updated

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.

Affected Software

8 affected componentsFixes available
pip/django>=4.2<4.2.30
4.2.30
pip/django>=5.2<5.2.13
5.2.13
pip/django>=6.0<6.0.4
6.0.4
djangoproject Django>=4.2<4.2.30
djangoproject Django>=5.2<5.2.13
djangoproject Django>=6.0<6.0.4
alpine/py3-django<4.2.30-r0
4.2.30-r0
alpine/py3-django<5.2.13-r0
5.2.13-r0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade pip/Django to a version that resolves this vulnerability.

    Fixed in 4.2.30
  2. Upgrade

    Upgrade pip/Django to a version that resolves this vulnerability.

    Fixed in 5.2.13
  3. Upgrade

    Upgrade pip/Django to a version that resolves this vulnerability.

    Fixed in 6.0.4
  4. Upgrade

    Upgrade alpine/py3-django to a version that resolves this vulnerability.

    Fixed in 4.2.30-r0
  5. Upgrade

    Upgrade alpine/py3-django to a version that resolves this vulnerability.

    Fixed in 5.2.13-r0
  6. Upgrade

    Upgrade Django to a version that resolves this vulnerability.

    Fixed in 6.0.4
  7. Upgrade

    Upgrade Django to a version that resolves this vulnerability.

    Fixed in 5.2.13
  8. Upgrade

    Upgrade Django to a version that resolves this vulnerability.

    Fixed in 4.2.30

Event History

Apr 7, 2026
CVE Published
via MITRE·02:22 PM
Data Sourced
via MITRE·02:22 PM
DescriptionWeakness
Data Sourced
via NVD·03:17 PM
DescriptionSeverityWeakness
Data Sourced
via OSV·03:17 PM
DescriptionSeverityAffected Software
Advisory Published
via GitHub·03:30 PM
Data Sourced
via GitHub·03:30 PM
DescriptionSeverityWeaknessAffected Software
Oct 26, 2026
Data Sourced
via NVD·09:10 PM
RemedyAffected Software

Company

Resources

Contact

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