CVE-2026-25673: Django Uncontrolled Resource Consumption Vulnerability
Summary
CVE-2026-25673: Django vulnerable to Uncontrolled Resource Consumption. Affects django across 3 version ranges.
>= 4.2, < 4.2.29
>= 5.2, < 5.2.12
>= 6.0, < 6.0.3
Fixed in 4.2.29, 5.2.12 or 6.0.3, depending on the release line you run. How to fix ↓
Also tracked for
- django · Bitnami
The same CVE-2026-25673 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
Django is a high-level Python web framework that encourages rapid development and clean, pragmatic design. It is widely used for building web applications and provides a robust set of features, including an ORM, authentication, and an admin interface. However, certain versions of Django are vulnerable to an issue that can lead to denial of service due to uncontrolled resource consumption when processing specific Unicode characters in URLs.
Vulnerability Detail
An issue was discovered in Django versions 6.0 before 6.0.3, 5.2 before 5.2.12, and 4.2 before 4.2.29. The vulnerability arises from the URLField.to_python() method, which calls urllib.parse.urlsplit(). On Windows, this method performs NFKC normalization that is disproportionately slow for certain Unicode characters. A remote attacker can exploit this vulnerability by sending large URL inputs containing these characters, potentially leading to a denial of service. Unsupported Django series such as 5.0.x, 4.1.x, and 3.2.x may also be affected but were not evaluated.
How To Fix
Latest published version: 6.1.2 as of 22 Oct 2026
pip install --upgrade "django==6.1.2"Upgrading to it may include breaking changes; the versions below are the minimum fixed release for this vulnerability.
If you can't move to the latest
The minimum fixed version depends on the release line you run.
-
>= 4.2, < 4.2.294.2.29pip install --upgrade "django==4.2.29" -
>= 5.2, < 5.2.125.2.12pip install --upgrade "django==5.2.12" -
>= 6.0, < 6.0.36.0.3pip install --upgrade "django==6.0.3"
Tip — Not sure which release line you're on? Vulert can find the fix for the version you are using. Scan free →
Workaround
As a temporary workaround, you can implement input validation to restrict the length and character set of URLs processed by your application, thereby mitigating the risk of denial of service from large URL inputs.
Conclusion
The Django vulnerability CVE-2026-25673 poses a significant risk of denial of service due to uncontrolled resource consumption when processing specific Unicode characters in URLs. It is crucial for users of affected versions to update to the latest patched versions to mitigate this risk.
See every vulnerability recorded for django →
FAQ
Django versions 6.0 before 6.0.3, 5.2 before 5.2.12, and 4.2 before 4.2.29 are affected. Unsupported versions like 5.0.x, 4.1.x, and 3.2.x may also be impacted.
The CVSS score of this vulnerability is 7.5, indicating a high severity level that could lead to denial of service.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. You can check if your application is affected by visiting the Vulert playground at Vulert Scanner.
If an immediate update is not possible, implement input validation to restrict URL lengths and character sets as a temporary workaround.
The vulnerability was reported by Seokchan Yoon.
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