Resource exhaustion in Djangoproject Django
CVE-2025-27556
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.011 (63.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 63.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.011 · change: +0.000
Affected products
- Djangoproject Django — versions 5.0, 5.1
- Microsoft Windows
Weakness classification (CWE)
Public proof-of-concept exploits
References
- docs.djangoproject.com/en/dev/releases/security/ (Vendor Advisory)
- groups.google.com/g/django-announce (Vendor Advisory)
- www.djangoproject.com/weblog/2025/apr/02/security-releases/ (Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-27556?
- CVE-2025-27556 is a medium-severity vulnerability in Djangoproject Django, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.8/10. Published 2025-04-02.
- How severe is CVE-2025-27556?
- Medium severity. CVSS v3 base score is 5.8 out of 10.
- Is CVE-2025-27556 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.