Potential denial-of-service vulnerability in URLField via Unicode normalization on Windows (djangoproject Django)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.84 % · percentile 58 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- DSF
- NVD status
- Modified
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.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption
- CWE-770 — Allocation of Resources Without Limits or Throttling
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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CISA-ADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Advisories
- GHSA-8p8v-wh79-9r56 — Django vulnerable to Uncontrolled Resource Consumption
- PYSEC-2026-2448 — Django vulnerable to Uncontrolled Resource Consumption
European references
- ENISA EUVD · EUVD-2026-9294
- GCVE · GCVE-0-2026-25673
CERT-FR advisories
- CERTFR-2026-AVI-1056 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*≥ 4.2.0 < 4.2.29cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*≥ 5.2 < 5.2.12cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*≥ 6.0 < 6.0.3
Affected products
| Product | Versions |
|---|---|
| djangoproject · Django | affected 6.0 < 6.0.3 ; unaffected 6.0.3 ; affected 5.2 < 5.2.12 ; unaffected 5.2.12 ; affected 4.2 < 4.2.29 ; unaffected 4.2.29 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |