CVE-2026-25673
HIGH7.5EPSS 0.24%Potential denial-of-service vulnerability in URLField via Unicode normalization on Windows
Published: 3/3/2026Modified: 4/21/2026
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 packages (2)
- Bitnami/django>= 4.2.0, < 4.2.29, >= 5.2.0, < 5.2.12, >= 6.0.0, < 6.0.3
- PyPI/django>= 6.0, < 6.0.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-25673
- PATCHhttps://github.com/django/django
- WEBhttps://docs.djangoproject.com/en/dev/releases/security
- WEBhttps://docs.djangoproject.com/en/dev/releases/security/
- WEBhttps://groups.google.com/g/django-announce
- WEBhttps://www.djangoproject.com/weblog/2026/mar/03/security-releases
- WEBhttps://www.djangoproject.com/weblog/2026/mar/03/security-releases/