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CVE-2026-25673NVD
Vulnerability Summary
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.
`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.
CVSS v3.1 Base Metrics — Score 7.5 (HIGH)
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Affected & Patched Versions
- Djangoproject Django >= 4.2.0 and < 4.2.29
- Djangoproject Django >= 5.2 and < 5.2.12
- Djangoproject Django >= 6.0 and < 6.0.3
- Djangoproject Django 4.2.29
- Djangoproject Django 5.2.12
- Djangoproject Django 6.0.3
External 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