Vulnerability Description
An issue was discovered in Django 5.1 before 5.1.8 and 5.0 before 5.0.14. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.views.LoginView, django.contrib.auth.views.LogoutView, and django.views.i18n.set_language are subject to a potential denial-of-service attack via certain inputs with a very large number of Unicode characters.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Djangoproject | Django | >= 5.0, < 5.0.14 |
| Microsoft | Windows | - |
Related Weaknesses (CWE)
References
- https://docs.djangoproject.com/en/dev/releases/security/Vendor Advisory
- https://groups.google.com/g/django-announceVendor Advisory
- https://www.djangoproject.com/weblog/2025/apr/02/security-releases/Vendor Advisory
- http://www.openwall.com/lists/oss-security/2025/04/02/2Mailing ListThird Party Advisory
FAQ
What is CVE-2025-27556?
CVE-2025-27556 is a vulnerability with a CVSS score of 5.8 (MEDIUM). An issue was discovered in Django 5.1 before 5.1.8 and 5.0 before 5.0.14. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.views.LoginView, django.contrib.auth.views.Lo...
How severe is CVE-2025-27556?
CVE-2025-27556 has been rated MEDIUM with a CVSS base score of 5.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-27556?
Check the references section above for vendor advisories and patch information. Affected products include: Djangoproject Django, Microsoft Windows.