Auth bypass in Mattermost
CVE-2025-3227
Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly enforce channel member management permissions in playbook runs, allowing authenticated users without the 'Manage Channel Members' permission to add or remove users from public and private channels by manipulating playbook run participants when the run is linked to a channel.
Vulnerability class: Broken Access Control
EPSS: 0.002 (11.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Mattermost — versions 10.5.0, 9.11.0, 10.8.0
- Mattermost Mattermost_server — versions 10.8.0
Weakness classification (CWE)
References
- responsibledisclosure@mattermost.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-3227?
- CVE-2025-3227 is a medium-severity vulnerability in Mattermost, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2025-06-20.
- How severe is CVE-2025-3227?
- Medium severity. CVSS v3 base score is 4.3 out of 10.