CVE-2021-32052: Header injection possible in Django

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-05-06 · updated 2026-06-17
Weakness: CWE-79

Description

In Django 2.2 before 2.2.22, 3.1 before 3.1.10, and 3.2 before 3.2.2 (with Python 3.9.5+), URLValidator does not prohibit newlines and tabs (unless the URLField form field is used). If an application uses values with newlines in an HTTP response, header injection can occur. Django itself is unaffected because HttpResponse prohibits newlines in HTTP headers.

Affected products

Django: from 2.2 before 2.2.22; from 3.1 before 3.1.10; from 3.2 before 3.2.2 — fixed in 2.2.22, 3.1.10, 3.2.2
Fedoraproject Fedora: 34
Pypi Django: from 2.2 before 2.2.22; from 3.1 before 3.1.10; from 3.2 before 3.2.2; 2.2, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5 (+28) — fixed in 2.2.22, 3.1.10, 3.2.2

How to fix

Upgrade to a fixed version: Django 2.2.22, 3.1.10, 3.2.2; Pypi Django 2.2.22, 3.1.10, 3.2.2. Check the vendor advisory for mitigations.

References

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