Vulnerability advisory

GHSA-mvfq-ggxm-9mc5

Django vulnerable to ASGI header spoofing via underscore/hyphen conflation

Published Apr 7, 2026Updated Sep 10, 2026OSV record ↗

Also known as BIT-django-2026-3902CVE-2026-3902PYSEC-2026-51

Severity

CVSS 3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected versions

django PyPI

All django advisories →

Affected	Fixed in
`6.0` to before 6.0.4	`6.0.4`Advisories →
Also listed as affected (4) `6.0` `6.0.1` `6.0.2` `6.0.3`
`5.2` to before 5.2.13	`5.2.13`Advisories →
Also listed as affected (13) `5.2` `5.2.1` `5.2.10` `5.2.11` `5.2.12` `5.2.2` `5.2.3` `5.2.4` `5.2.5` `5.2.6` `5.2.7` `5.2.8` `5.2.9`
`4.2` to before 4.2.30	`4.2.30`Advisories →
Also listed as affected (30) `4.2` `4.2.1` `4.2.10` `4.2.11` `4.2.12` `4.2.13` `4.2.14` `4.2.15` `4.2.16` `4.2.17` `4.2.18` `4.2.19` `4.2.2` `4.2.20` `4.2.21` `4.2.22` `4.2.23` `4.2.24` `4.2.25` `4.2.26` `4.2.27` `4.2.28` `4.2.29` `4.2.3` `4.2.4` `4.2.5` `4.2.6` `4.2.7` `4.2.8` `4.2.9`

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.

GHSA-mvfq-ggxm-9mc5

Affected versions

django PyPI

Description

References