Description

Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.4, Werkzeug's safe_join function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely. This issue has been patched in version 3.1.4.

INFO

Published Date :

2025-11-29T02:28:34.524Z

Last Modified :

2025-12-01T15:35:25.271Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2025-66221 vulnerability.

Vendors Products
Microsoft
  • Windows
Palletsprojects
  • Werkzeug
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-66221.

URL Resource
https://github.com/pallets/werkzeug/commit/4b833376a45c323a189cd11d2362bcffdb1c0c13 cve-icon cve-icon cve-icon
https://github.com/pallets/werkzeug/releases/tag/3.1.4 cve-icon cve-icon cve-icon
https://github.com/pallets/werkzeug/security/advisories/GHSA-hgf8-39gv-g3f2 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-66221 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-66221 cve-icon
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CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
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Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
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SS Confidentiality
SS Integrity
SS Availability
Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact