CVE-2026-19603 Private channel ID disclosure via user status endpoints

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10, 11.10.x = 11.10.1 fail to sanitize the active channel field returned by the user status API endpoints, which allows an authenticated user to learn the channel ID of a private channel another user is actively viewing via the...