CVE-2026-10080
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fails to validate WebSocket command field types which allows an authenticated user to crash the plugin process and deny service to all Boards users via a custom_focalboard_SUBSCRIBE_TEAM message with a non-string teamId.. Mattermost Advisory ID: MMSA-2026-00687
Published:Aug 17, 2026
Last Modified:Aug 18, 2026
EPS:Aug 17, 2026
EPSS Score:0.00289
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Mattermost
Product
Mattermost
Mattermost
Mattermost
Vendor
Mattermost
Product
Mattermost Server
Mattermost
Mattermost Server
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
No CAPEC recorded yet
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
