CVE-2026-27659

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to properly validate CSRF tokens in the /api/v4/access_control_policies/{policy_id}/activate endpoint, which allows an attacker to trick an admin into changing access control policy active status via a crafted request.. Mattermost Advisory ID: MMSA-2026-00578

CVSS v3 4.6 MEDIUM

4.6^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.1 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

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

History

26 Mar 2026, 18:49

Type	Values Removed	Values Added
First Time		Mattermost Mattermost mattermost Server
Summary		(es) Las versiones de Mattermost 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 no validan correctamente los tokens CSRF en el endpoint /api/v4/access_control_policies/{policy_id}/activate, lo que permite a un atacante engañar a un administrador para que cambie el estado activo de una política de control de acceso mediante una solicitud manipulada. ID de Aviso de Mattermost: MMSA-2026-00578
CPE		cpe:2.3:a:mattermost:mattermost_server::::::::
References	~~() https://mattermost.com/security-updates -~~	() https://mattermost.com/security-updates - Vendor Advisory

25 Mar 2026, 17:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-25 17:16

Updated : 2026-03-26 18:49

NVD link : CVE-2026-27659

Mitre link : CVE-2026-27659

CVE.ORG link : CVE-2026-27659

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-352

Cross-Site Request Forgery (CSRF)

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