CVE-2025-13821
February 16, 2026
Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 fail to sanitize sensitive data in WebSocket messages which allows authenticated users to exfiltrate password hashes and MFA secrets via profile nickname updates or email verification events. Mattermost Advisory ID: MMSA-2025-00560
Affected Packages
github.com/mattermost/mattermost (GO):
Affected version(s) >=v11.2.0 <v11.2.2Fix Suggestion:
Update to version v11.2.2github.com/mattermost/mattermost/server/v8 (GO):
Affected version(s) >=v8.0.0-20230429093631-aac4f2337933 <v8.0.0-20251210191531-cd17b61de41bFix Suggestion:
Update to version v8.0.0-20251210191531-cd17b61de41bgithub.com/mattermost/mattermost (GO):
Affected version(s) >=v11.1.0 <v11.1.3Fix Suggestion:
Update to version v11.1.3github.com/mattermost/mattermost (GO):
Affected version(s) >=v10.11.0 <v10.11.9Fix Suggestion:
Update to version v10.11.9Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.7
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Exposure of Sensitive Information to an Unauthorized Actor
EPSS
Base Score:
0.03
