CVE-2026-53878

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.

How to fix CVE-2026-53878

To remediate CVE-2026-53878, upgrade the affected package to a fixed version below.

• —upgrade to 5.2.16 or later
• —no fix listed
• —upgrade to 5.2.16 or later

Is CVE-2026-53878 being exploited?

Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• >= 5.2.0, < 5.2.16, >= 6.0.0, < 6.0.7
• from 0
• >= 5.2, < 5.2.16, >= 6.0, < 6.0.7

CVSS scores

References (5)

• ADVISORYgroups.google.com/g/django-announce
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-53878
• PATCHdocs.djangoproject.com/en/dev/releases/security/
• PATCHwww.djangoproject.com/weblog/2026/jul/07/security-releases/
• WEB