CVE-2026-21860

5.3 MEDIUM
Published: January 08, 2026 Modified: February 02, 2026
View on NVD

Description

Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.5, Werkzeug's safe_join function allows path segments with Windows device names that have file extensions or trailing spaces. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. Windows still accepts them with any file extension, such as CON.txt, or trailing spaces such as CON. This issue has been patched in version 3.1.5.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.3 / 10.0
EPSS (Exploit Probability)
0.0%
6th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

microsoft palletsprojects