What’s Vulnerable › Vulnerabilities

CVE-2026-53878: Header injection possibility since DomainNameValidator accepted newlines in input

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-07 · updated 2026-10-25
• Weakness: CWE-144

Description

An issue was discovered in Django 6.0 before 6.0.7 and 5.2 before 5.2.16. `DomainNameValidator` does not prohibit newlines in domain names (unless used via a form field, since `CharField` strips newlines). 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. 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 Bence Nagy for reporting this issue.

Affected products

• Django: from 5.2 before 5.2.16; from 6.0 before 6.0.7 — fixed in 5.2.16, 6.0.7
• Pypi Django: before 5.2.16; from 6.0.0 before 6.0.7; 1.0.1, 1.0.2, 1.0.3, 1.0.4, 1.1, 1.1.1 (+424) — fixed in 5.2.16, 6.0.7

How to fix

Upgrade to a fixed version: Django 5.2.16, 6.0.7; Pypi Django 5.2.16, 6.0.7. Check the vendor advisory for mitigations.

References

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

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