CVE-2026-7387 HIGH

CVE-2026-7387: Mattermost group syncable endpoints allow privilege escalation via scheme_admin

Vendor Mattermost
Product Mattermost
Weakness CWE-863 · Incorrect authorization
Published June 12, 2026
Last update June 13, 2026
View on NVD All CVEs

CVSS base score

8.8/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

June 12, 2026 CVE published
June 13, 2026 Record updated