Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the {{manage_secure_connections}} permission to obtain remote cluster authentication tokens via a PATCH request to the remote cluster endpoint.. Mattermost Advisory ID: MMSA-2026-00662
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:NA:N6.5/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NOther