Django: Inefficient Algorithmic Complexity
CVE-2025-64458 is a high-severity inefficient algorithmic complexity vulnerability in Django, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 5.2.8, 5.1.14, 4.2.26 as the first without the flaw, so updating Django to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.91% chance of exploitation within 30 days, higher than 80% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Django to 5.2.8 or 5.1.14 or 4.2.26, whichever matches your release line, or a later version.
- Read the advisory on docs.djangoproject.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Django | Django | 5.2 up to, but not including, 5.2.8; 5.1 up to, but not including, 5.1.14; 4.2 up to, but not including, 4.2.26 | 5.2.8, 5.1.14, 4.2.26 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CISA (ADP).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Inefficient Algorithmic Complexity
An 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.
More Inefficient Algorithmic Complexity vulnerabilities (CWE-407)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
- groups.google.com/g/django-announceMailing List
Other vulnerabilities in Django
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.5 High severity
Recent Inefficient Algorithmic Complexity vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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