Denial of service in Django on Windows

1) Resource management error

EUVDB-ID: #VU106924

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-27556

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources during NFKC normalization on Windows. A remote attacker can pass a very large number of Unicode characters to django.contrib.auth.views.LoginView(), django.contrib.auth.views.LogoutView(), or django.views.i18n.set_language() methods and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Django: 5.0 - 5.1.7

CPE2.3

• cpe:2.3:a:django_software_foundation:django:5.1.7:*:*:*:*:*:*:*

External links

https://www.openwall.com/lists/oss-security/2025/04/02/2
https://www.djangoproject.com/weblog/2025/apr/02/security-releases/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.