pallets werkzeug up to 3.1.4 windows device name

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability was found in pallets werkzeug up to 3.1.4. It has been declared as problematic. The affected element is an unknown function. Executing a manipulation can lead to windows device name. This vulnerability is tracked as CVE-2026-21860. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in pallets werkzeug up to 3.1.4. This vulnerability affects some unknown processing. The manipulation with an unknown input leads to a windows device name vulnerability. The CWE definition for the vulnerability is CWE-67. The product constructs pathnames from user input, but it does not handle or incorrectly handles a pathname containing a Windows device name such as AUX or CON. This typically leads to denial of service or an information exposure when the application attempts to process the pathname as a regular file. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-21860 since 01/05/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 282536 (Linux Distros Unpatched Vulnerability : CVE-2026-21860), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.1.5 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (282536) and EUVD (EUVD-2026-1425). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Windows device name
CWE: CWE-67
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 282536
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-21860

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: werkzeug 3.1.5

Timelineinfo

01/05/2026 CVE reserved
01/08/2026 +3 days Advisory disclosed
01/08/2026 +0 days VulDB entry created
02/02/2026 +25 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-21860 (🔒)
GCVE (CVE): GCVE-0-2026-21860
GCVE (VulDB): GCVE-100-340192
EUVD: 🔒

Entryinfo

Created: 01/08/2026 19:55
Updated: 02/02/2026 23:54
Changes: 01/08/2026 19:55 (65), 01/10/2026 15:44 (2), 02/02/2026 19:28 (10), 02/02/2026 23:54 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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