CVE-2026-4273

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575

CVSS v3 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

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::::::::

History

14 Oct 2026, 20:10

Type	Values Removed	Values Added
Summary		(es) Las versiones de Mattermost 11.5.x menor o igual que 11.5.1, 10.11.x menor o igual que 10.11.13 no validan que el RefreshedToken difiera del token de invitación original durante la confirmación de invitación de clúster remoto, lo que permite a un atacante autenticado eludir la rotación de tokens y reutilizar el token de invitación original mediante el envío de una confirmación de invitación manipulada con un RefreshedToken que coincida con el token original. ID de Aviso de Mattermost: MMSA-2026-00575

Information

Published : 2026-05-18 08:16

Updated : 2026-10-14 20:10

NVD link : CVE-2026-4273

Mitre link : CVE-2026-4273

CVE.ORG link : CVE-2026-4273

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-863

Incorrect Authorization

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