CVE-2026-25673Potential denial-of-service vulnerability in URLField via Unicode normalization on Windows
Updated under an hour ago ()
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It affects djangoproject Django and 3 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- DSF
- NVD analysis
- Modified
- Record last updated
- Jul 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
djangoproject Django djangoproject:django (from the name) | from 6.0 before 6.0.3; 6.0.3 not affected; from 5.2 before 5.2.12; 5.2.12 not affected; from 4.2 before 4.2.29; 4.2.29 not affected | CNA record |
Red Hat Red Hat Ansible Automation Platform 2 redhat:ansible_automation_platform | 2 | CISA ADP |
Red Hat Red Hat Discovery 2 redhat:discovery | 2 | CISA ADP |
Red Hat Red Hat Satellite 6 redhat:satellite | 6 | CISA ADP |
djangoproject django djangoproject:django | from 4.2.0 before 4.2.29; from 5.2 before 5.2.12; from 6.0 before 6.0.3 | NVD |
References
- https://docs.djangoproject.com/en/dev/releases/security/vendor-advisory, patch
- https://groups.google.com/g/django-announcemailing-list, release-notes
- https://www.djangoproject.com/weblog/2026/mar/03/security-releases/vendor-advisory, patch
- 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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.