CVE-2026-10527
Published:August 17, 2026
Updated:September 01, 2026
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
Affected Packages
https://github.com/mattermost/mattermost-plugin-boards.git (GITHUB):
Affected version(s) >=v9.0.0 <v9.2.6Fix Suggestion:
Update to version v9.2.6github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.7.0 <v11.7.7Fix Suggestion:
Update to version v11.7.7github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.22Fix Suggestion:
Update to version v10.11.22github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.8.0 <v11.8.4Fix Suggestion:
Update to version v11.8.4Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Weakness Type (CWE)
Incorrect Authorization
EPSS
Base Score:
0.15