Mattermost fails to check the "Show Full Name" setting when rendering the result for the /plugins/focalboard/api/v2/users API call, allowing an attacker to learn the full name of a board owner.
A missing permissions check in the /plugins/playbooks/api/v0/runs API in Mattermost allows an attacker to list and view playbooks belonging to a team they are not a member of.
A missing permissions check in Mattermost Playbooks in Mattermost allows an attacker to modify a playbook via the /plugins/playbooks/api/v0/playbooks/[playbookID] API.