CVE-2025-64458: djangoproject django Inefficient Algorithmic Complexity

Vulnerability summary

CVE-2025-64458 is a high (CVSS 7.5) Inefficient Algorithmic Complexity vulnerability in djangoproject django. EPSS estimates a 1.91% chance of exploitation in the next 30 days, higher than 79.4% of scored vulnerabilities.

Timeline

1. 05-11-2025
   PublishedVulnerability first disclosed.
2. 05-11-2025
   Last modifiedVulnerability information updated.

Description

An issue was discovered in 5.1 before 5.1.14, 4.2 before 4.2.26, and 5.2 before 5.2.8. NFKC normalization in Python is slow on Windows. As a consequence, `django.http.HttpResponseRedirect`, `django.http.HttpResponsePermanentRedirect`, and the shortcut `django.shortcuts.redirect` were subject to a potential denial-of-service attack via certain inputs with a very large number of Unicode 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.

• CWE-407Inefficient Algorithmic ComplexityAn algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.