CVE-2026-6342

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same prefix as a whitelisted group. Mattermost Advisory ID: MMSA-2026-00601

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://mattermost.com/security-updates	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::

History

14 Oct 2026, 20:10

Type	Values Removed	Values Added
Summary		(es) Las versiones de los plugins de Mattermost menor o igual que 11.5 11.1.5 10.13.11 11.3.4.0 no comprueban adecuadamente los espacios de nombres válidos, lo que permite a los usuarios de plugins crear suscripciones a grupos que no estaban en la lista blanca mediante la creación de grupos que comparten el mismo prefijo que un grupo en la lista blanca. ID de aviso de Mattermost: MMSA-2026-00601

Information

Published : 2026-05-18 08:16

Updated : 2026-10-14 20:10

NVD link : CVE-2026-6342

Mitre link : CVE-2026-6342

CVE.ORG link : CVE-2026-6342

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-863

Incorrect Authorization

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