CVE-2026-6689
MediumCVSS 4.3Exploitation Probability (EPSS)
Low risk5th percentile — higher than 5% of all known CVEs
Summary
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, and 10.11.x <= 10.11.16 fail to enforce proper permissions when creating teams, allowing authenticated users with PermissionCreateTeam but without PermissionInviteUser to modify team invite settings.
Risk Assessment
The organization may be exposed to unauthorized changes in team settings, potentially leading to uncontrolled access to teams and data.
Recommendation
It is recommended to update Mattermost to the latest version to ensure proper enforcement of permissions when creating teams.
Original NVD description (English source)
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Fail to enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation (the check was only applied on update/patch), which allows an authenticated user holding PermissionCreateTeam but not PermissionInviteUser on the resulting team to configure invite-controlled team settings (make the team publicly joinable via open invite and/or constrain membership via allowed domains) that they are not permitted to set on an existing team via POST /api/v4/teams with allow_open_invite: true and/or a non-empty allowed_domains in the request body.. Mattermost Advisory ID: MMSA-2026-00655