Description
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
Low
Affected products
- Mattermost / Mattermost11.7.0 – 11.7.0
- Mattermost / Mattermost11.6.0 – 11.6.2
- Mattermost / Mattermost11.5.0 – 11.5.5
- Mattermost / Mattermost10.11.0 – 10.11.17
- Mattermost / Mattermost11.8.0 – 11.8.0
- Mattermost / Mattermost11.7.1 – 11.7.1
- Mattermost / Mattermost11.6.3 – 11.6.3
- Mattermost / Mattermost11.5.6 – 11.5.6
- Mattermost / Mattermost10.11.18 – 10.11.18