Description
An issue was discovered in 6.0 before 6.0.3, 5.2 before 5.2.12, and 4.2 before 4.2.29. `URLField.to_python()` in Django calls `urllib.parse.urlsplit()`, which performs NFKC normalization on Windows that is disproportionately slow for certain Unicode characters, allowing a remote attacker to cause denial of service via large URL inputs containing these characters. 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 Seokchan Yoon for reporting this issue.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
djangoproject Django
Default version status: unaffected
6.0 to < 6.0.3affected6.0.3unaffected5.2 to < 5.2.12affected5.2.12unaffected4.2 to < 4.2.29affected4.2.29unaffected
References
- https://docs.djangoproject.com/en/dev/releases/security/ ↗
- https://groups.google.com/g/django-announce ↗
- https://www.djangoproject.com/weblog/2026/mar/03/security-releases/ ↗
- https://access.redhat.com/security/cve/CVE-2026-25673 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2444115 ↗
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25673.json ↗