GO-2026-6286 Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel in github.com/mattermost/mattermost-server

Mattermost doesn't restrict roleupdated websocket event broadcasts to members of the affected team or channel in github.com/mattermost/mattermost-server...

Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel

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 restrict roleupdated websocket event broadcasts to members of the affected team or channel, which allows an authenticated attacker with guest-level access to observe permission scheme change...

GHSA-RP4V-QC77-PHM4 Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel

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 restrict roleupdated websocket event broadcasts to members of the affected team or channel, which allows an authenticated attacker with guest-level access to observe permission scheme change...

Information Exposure

Overview Affected versions of this package are vulnerable to Information Exposure via the roleupdated websocket event broadcast process. An attacker can gain unauthorized access to permission scheme change notifications for private teams by connecting to the websocket as an authenticated user wit...

CVE-2026-3433 Mattermost fails to scope role_updated websocket events to authorized team and channel members

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 restrict roleupdated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with guest-level access to observe permission scheme change...

CVE-2026-3433

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 restrict roleupdated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with guest-level access to observe permission scheme change...

CVE-2026-3433: Exposure of Sensitive Information to an Unauthorized Actor

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 restrict roleupdated websocket event broadcasts to members of the affected team or channel which allows an authenticated attacker with guest-level access to observe permission scheme change...