CVE-2026-26230
Team Admin Privilege Escalation to Demote Members to Guest
CVSS Score
3.8
EPSS Score
0.0%
EPSS Percentile
0th
Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531
| CWE | CWE-863 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Mar 16, 2026 |
| Last Updated | Mar 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
Mattermost / Mattermost
10.11.0 ≤ 10.11.10
Credits
hackit_bharat