Resource exhaustion in Djangoproject Django

CVE-2026-25673

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.

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.4th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-25673: held from 0.007 to 0.011.

EPSS over last 30 days · oldest: 0.007 · newest: 0.011 · change: +0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-25673?
CVE-2026-25673 is a high-severity vulnerability in Djangoproject Django, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-03-03.
How severe is CVE-2026-25673?
High severity. CVSS v3 base score is 7.5 out of 10.