CVE-2025-64458VulnerabilityPublished 5 Nov 2025

CVE-2025-64458: djangoproject Django · Inefficient Algorithmic Complexity

Affects djangoproject DjangoSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.9% chance of exploitation in 30 days – higher than 79% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
PyPIdjango`pkg:pypi/django`Other threats	Affected =5.2 =5.1 =4.2	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2025-64458, organizations should promptly upgrade affected Django versions to the fixed releases: 5.1.14 or later, 4.2.26 or later, and 5.2.8 or later. If immediate patching is not feasible, consider the following specific mitigations: 1) Implement input validation and size limits on HTTP request parameters that are processed by redirect functions to reject or truncate excessively large Unicode inputs before normalization occurs. 2) Deploy Web Application Firewalls (WAFs) with custom rules to detect and block requests containing unusually large Unicode payloads targeting redirect endpoints. 3) Monitor server performance metrics and logs for signs of abnormal CPU usage or request patterns indicative of this DoS attack. 4) Where possible, avoid running Django applications on Windows servers until patched, or isolate such servers behind additional filtering layers. 5) Review application code to minimize reliance on redirect functions that perform Unicode normalization or replace them with safer alternatives if available. 6) Employ rate limiting on endpoints that use these redirect functions to reduce the impact of potential abuse. These targeted mitigations complement patching and help reduce the attack surface and impact of exploitation.

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.

Impact

The primary impact of CVE-2025-64458 is a denial-of-service condition caused by resource exhaustion on affected Django web servers running on Windows. Organizations relying on Django for web applications may experience service outages or degraded performance when targeted by attackers sending maliciously crafted requests with large Unicode payloads. This can disrupt business operations, degrade user experience, and potentially cause cascading failures in dependent systems. Since the vulnerability affects core redirect functions, it may impact a wide range of Django-based applications that use these common HTTP response utilities. The lack of authentication or user interaction requirements means that attackers can exploit this vulnerability remotely and anonymously, increasing the risk of widespread attacks. Although no data confidentiality or integrity is compromised, the availability impact can be critical for high-traffic or mission-critical web services. The vulnerability is especially relevant for organizations hosting Django applications on Windows servers, which are more susceptible due to the slow NFKC normalization implementation on that platform. Enterprises in sectors such as finance, healthcare, e-commerce, and government that rely on Django for web infrastructure could face significant operational disruption if exploited.

CWE-407Inefficient Algorithmic Complexity (opens in a new tab)
Class weaknessLikelihood of exploit: Low
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.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 15:51 UTC

WeaknessesCWE-407

Technical details

References

Community reviews

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