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.
Metrics
Affected Vendors & Products
References
History
Thu, 05 Mar 2026 00:15:00 +0000
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| Weaknesses | CWE-770 | |
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threat_severity
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threat_severity
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Wed, 04 Mar 2026 15:00:00 +0000
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Djangoproject
Djangoproject django |
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Djangoproject
Djangoproject django |
Tue, 03 Mar 2026 16:15:00 +0000
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cvssV3_1
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Tue, 03 Mar 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
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| 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. | |
| Title | Potential denial-of-service vulnerability in URLField via Unicode normalization on Windows | |
| Weaknesses | CWE-400 | |
| References |
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Status: PUBLISHED
Assigner: DSF
Published: 2026-03-03T14:28:28.601Z
Updated: 2026-03-03T15:26:02.764Z
Reserved: 2026-02-04T18:27:10.657Z
Link: CVE-2026-25673
Updated: 2026-03-03T15:25:39.933Z
Status : Awaiting Analysis
Published: 2026-03-03T15:16:19.103
Modified: 2026-03-03T21:52:29.877
Link: CVE-2026-25673
ReportizFlow