Inefficient Algorithmic Complexity Affecting django package, versions [,4.2.26)[5.0a1,5.1.14)[5.2a1,5.2.8)


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

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  • Snyk IDSNYK-PYTHON-DJANGO-13837025
  • published6 Nov 2025
  • disclosed5 Nov 2025
  • creditSeokchan Yoon

Introduced: 5 Nov 2025

NewCVE-2025-64458  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

Upgrade Django to version 4.2.26, 5.1.14, 5.2.8 or higher.

Overview

Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design.

Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via the HttpResponseRedirect and HttpResponsePermanentRedirect functions when processing inputs containing a very large number of Unicode characters, due to slow NFKC normalization on Windows. An attacker can cause excessive resource consumption and disrupt service availability.

Note: This is only exploitable on Windows.

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

CVSS Base Scores

version 4.0
version 3.1