CVE-2026-6341

Published: May 18, 2026Modified: Jun 17, 2026

4.3

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Exploitability: 2.8 / Impact: 1.4

Source: responsibledisclosure@mattermost.com (Secondary)

Description

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to have API-level checks on which groups the user can create issues or attach comments to which allows a user that is member of multiple groups to create issues to a locked group via direct API requests. Mattermost Advisory ID: MMSA-2026-00602

Affected (3)

Products: Mattermost: Mattermost Server

Mattermost

1 product

Mattermost Server

Configuration A

3 vulnerable

Vulnerable Software	Affected Versions
Mattermost Mattermost Server	From 10.13.0 to 10.13.11
Mattermost Mattermost Server	From 11.1.0 to 11.1.5
Mattermost Mattermost Server	From 11.3.0 to 11.3.4

Related CWEs

CWE-863

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Vendor Advisory

Timeline

No history available yet.