Description
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
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected products
- Mattermost / Mattermost11.6.0 – 11.6.1
- Mattermost / Mattermost11.5.0 – 11.5.4
- Mattermost / Mattermost10.11.0 – 10.11.15
- Mattermost / Mattermost10.11.0 – 10.11.16
- Mattermost / Mattermost11.7.0 – 11.7.0
- Mattermost / Mattermost11.6.2 – 11.6.2
- Mattermost / Mattermost11.5.5 – 11.5.5
- Mattermost / Mattermost10.11.16 – 10.11.16
- Mattermost / Mattermost10.11.17 – 10.11.17