CVE-2025-12689

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://mattermost.com/security-updates	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::

History

13 Oct 2026, 11:10

Type	Values Removed	Values Added
Summary		(es) Las versiones de Mattermost 11.0.x menor o igual que 11.0.4, 10.12.x menor o igual que 10.12.2, 10.11.x menor o igual que 10.11.6 no verifican el campo de solicitud de WebSocket en busca de un formato UTF-8 correcto, lo que permite al atacante bloquear el complemento de Llamadas mediante el envío de una solicitud malformada.

Information

Published : 2025-12-17 19:16

Updated : 2026-10-13 11:10

NVD link : CVE-2025-12689

Mitre link : CVE-2025-12689

CVE.ORG link : CVE-2025-12689

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-1287

Improper Validation of Specified Type of Input

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