CVE-2026-16048 Channel member roles accept out-of-scope roles

Mattermost versions 11.8.x = 11.8.2, 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to restrict channel member role assignment to channel-scoped roles which allows a channel administrator to gain additional channel permissions via the channel member roles API.. Mattermost Advisory ID: MMSA-2026-00697...