Description
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 role_updated 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 notifications for private teams they are not a member of via the websocket connection.. Mattermost Advisory ID: MMSA-2026-00616
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected products
- Mattermost / Mattermost11.6.0 – 11.6.1
- Mattermost / Mattermost11.5.0 – 11.5.4
- Mattermost / Mattermost10.11.0 – 10.11.15
- Mattermost / Mattermost10.11.0 – 10.11.16
- Mattermost / Mattermost11.7.0 – 11.7.0
- Mattermost / Mattermost11.6.2 – 11.6.2
- Mattermost / Mattermost11.5.5 – 11.5.5
- Mattermost / Mattermost10.11.16 – 10.11.16
- Mattermost / Mattermost10.11.17 – 10.11.17