CVE-2025-27556: Django Potential Denial of Service (DoS) on Windows
(updated )
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.
References
- docs.djangoproject.com/en/dev/releases/security
- github.com/advisories/GHSA-wqfg-m96j-85vm
- github.com/django/django
- github.com/django/django/commit/2cb311f7b069723027fb5def4044d1816d7d2afd
- github.com/django/django/commit/39e2297210d9d2938c75fc911d45f0e863dc4821
- github.com/django/django/commit/8c6871b097b6c49d2a782c0d80d908bcbe2116f1
- github.com/django/django/commit/edc2716d01a6fdd84b173c02031695231bcee1f8
- github.com/pypa/advisory-database/tree/main/vulns/django/PYSEC-2025-14.yaml
- groups.google.com/g/django-announce
- nvd.nist.gov/vuln/detail/CVE-2025-27556
- www.djangoproject.com/weblog/2025/apr/02/security-releases
Code Behaviors & Features
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