CVE-2025-12689
December 17, 2025
Mattermost versions 11.0.x <= 11.0.4, 10.12.x <= 10.12.2, 10.11.x <= 10.11.6 fail to check WebSocket request field for proper UTF-8 format, which allows attacker to crash Calls plug-in via sending malformed request.
Affected Packages
github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.7Fix Suggestion:
Update to version v10.11.7github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.0.1-rc1 <v11.0.5Fix Suggestion:
Update to version v11.0.5github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.12.0 <v10.12.3Fix Suggestion:
Update to version v10.12.3Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Improper Validation of Specified Type of Input
EPSS
Base Score:
0.08
