GHSA-J6GG-R5JC-47CM Mattermost fails to properly restrict access to archived channel search API

Mattermost versions 11 fail to properly restrict access to archived channel search API which allows guest users to discover archived public channels via the /api/v4/teams/teamid/channels/searcharchived endpoint...

EUVD-2025-186556

Mattermost versions 11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events...