CVE-2026-2456

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

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

18 Mar 2026, 18:27

Type	Values Removed	Values Added
References	~~() https://mattermost.com/security-updates -~~	() https://mattermost.com/security-updates - Vendor Advisory
CPE		cpe:2.3:a:mattermost:mattermost_server::::::::
First Time		Mattermost Mattermost mattermost Server
Summary		(es) Versiones de Mattermost 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost no limita el tamaño de las respuestas de los puntos finales de acción de integración, lo que permite a un atacante autenticado causar el agotamiento de la memoria del servidor y denegación de servicio a través de un servidor de integración malicioso que devuelve una respuesta arbitrariamente grande cuando un usuario hace clic en un botón de mensaje interactivo. ID de Aviso de Mattermost: MMSA-2026-00571

16 Mar 2026, 14:19

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-16 14:19

Updated : 2026-03-18 18:27

NVD link : CVE-2026-2456

Mitre link : CVE-2026-2456

CVE.ORG link : CVE-2026-2456

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-789

Memory Allocation with Excessive Size Value

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