CVE-2026-10527
Boards plugin retains Board Admin rights for users demoted to System Guest
CVSS Score
6.3
EPSS Score
0.0%
EPSS Percentile
0th
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to reconcile SchemeAdmin flags with a user's current role which allows a user demoted to System Guest to retain Board Admin privileges and perform admin-only operations via the Boards REST API or UI.. Mattermost Advisory ID: MMSA-2026-00691
| CWE | CWE-863 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Aug 17, 2026 |
| Last Updated | Aug 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
Affected Versions
Mattermost / Mattermost
11.7.0 ≤ 11.7.6 10.11.0 ≤ 10.11.21 11.8.0 ≤ 11.8.3
Credits
ilent0