CVE-2026-7387

Published: Jun 12, 2026Modified: Jun 18, 2026

8.8

Vector

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

Exploitability: 2.8 / Impact: 5.9

Source: responsibledisclosure@mattermost.com (Secondary)

Description

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.. Mattermost Advisory ID: MMSA-2026-00665

Affected (3)

Products: Mattermost: Mattermost Server

Mattermost

1 product

Mattermost Server

Configuration A

3 vulnerable

Vulnerable Software	Affected Versions
Mattermost Mattermost Server	From 10.11.0 to 10.11.17
Mattermost Mattermost Server	From 11.5.0 to 11.5.5
Mattermost Mattermost Server	From 11.6.0 to 11.6.2

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.