Description
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
Problem types
CWE-201: Insertion of Sensitive Information Into Sent Data
Product status
11.6.0 (semver)
11.5.0 (semver)
10.11.0 (semver)
11.7.0
11.6.2
11.5.5
10.11.17
Credits
winfunc
References
mattermost.com/security-updates (MMSA-2026-00662)