{"id":"CVE-2025-27556","details":"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.","aliases":["BIT-django-2025-27556","GHSA-wqfg-m96j-85vm","PYSEC-2025-14"],"modified":"2026-07-15T10:14:46.285735026Z","published":"2025-04-02T00:00:00Z","related":["openSUSE-SU-2025:14986-1","openSUSE-SU-2026:10005-1","openSUSE-SU-2026:11270-1"],"database_specific":{"cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27556.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"5.0"},{"fixed":"5.0.14"},{"introduced":"5.1"},{"fixed":"5.1.8"}]},{"extracted_events":[{"introduced":"5.0"},{"fixed":"5.0.14"},{"introduced":"5.1"},{"fixed":"5.1.8"}],"source":"CPE_FIELD"},{"extracted_events":[{"introduced":"5.1"},{"fixed":"5.1.8"},{"introduced":"5.0"},{"fixed":"5.0.14"}],"source":"DESCRIPTION"}],"cna_assigner":"mitre"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2025/04/02/2"},{"type":"WEB","url":"https://docs.djangoproject.com/en/dev/releases/security/"},{"type":"WEB","url":"https://groups.google.com/g/django-announce"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27556.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-27556"},{"type":"ARTICLE","url":"https://www.djangoproject.com/weblog/2025/apr/02/security-releases/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/django/django","events":[{"introduced":"52821001bb62b764d73e63812133f199b8fef9eb"},{"fixed":"7c128112a6adff20b6d67a02c4098a2c10f88191"},{"introduced":"84d09a547fe35e10018ab242602ca76c29ca91a1"},{"fixed":"5773bc9cf929f4648da30cb9c472b816bb4db771"}],"database_specific":{"cpe":"cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"5.0"},{"fixed":"5.0.14"},{"introduced":"5.1"},{"fixed":"5.1.8"}],"source":"CPE_RANGE"}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-27556.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L"}]}