CVE-2025-11777
November 13, 2025
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint
Affected Packages
https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v10.11.0 <v10.11.4Fix Suggestion:
Update to version v10.11.4https://github.com/mattermost/mattermost.git (GITHUB):
Affected version(s) >=v10.5.0 <v10.5.12Fix Suggestion:
Update to version v10.5.12github.com/mattermost/mattermost-server (GO):
Affected version(s) >=v10.11.0 <v10.11.4Fix Suggestion:
Update to version v10.11.4github.com/mattermost/mattermost/server/v8 (GO):
Affected version(s) >=v8.0.0-20230429093631-aac4f2337933 <v8.0.0-20250905150616-ba86dfc5876bFix Suggestion:
Update to version v8.0.0-20250905150616-ba86dfc5876bgithub.com/mattermost/mattermost-server (GO):
Affected version(s) >=v10.5.0 <v10.5.12Fix Suggestion:
Update to version v10.5.12Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
2.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
3.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Incorrect Authorization
EPSS
Base Score:
0.04
