Detections
Analytics

Mattermost Server 10.5.x <= 10.5.12 / 10.11.x <= 10.11.4 / 10.12.x <= 10.12.1 / 11.0.x <= 11.0.3 Improper Authentication (MMSA-2025-00547)

critical Nessus Plugin ID 278110

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Synopsis

The remote host is missing a security update.

Description

The version of Mattermost Server installed on the remote host is affected by a vulnerability as referenced in the MMSA-2025-00547 advisory.

 - Mattermost versions 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12, 11.0.x <= 11.0.3 fail to properly validate OAuth state tokens during OpenID Connect authentication which allows an authenticated attacker with team creation privileges to take over a user account via manipulation of authentication data during the OAuth completion flow. This requires email verification to be disabled (default: disabled), OAuth/OpenID Connect to be enabled, and the attacker to control two users in the SSO system with one of them never having logged into Mattermost. (CVE-2025-12419)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Mattermost Server version 10.5.13, 10.11.5, 10.12.2, 11.0.4, 11.1.0 or later.

See Also

https://mattermost.com/security-updates/

Plugin Details

Severity: Critical

ID: 278110

File Name: mattermost_server_MMSA-2025-00547.nasl

Version: 1.2

Type: remote

Family: CGI abuses

Published: 12/10/2025

Updated: 12/12/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.3

CVSS v3

Risk Factor: Critical

Base Score: 9.9

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/a:mattermost:mattermost_server

Required KB Items: installed_sw/Mattermost Server

Patch Publication Date: 10/28/2025

Vulnerability Publication Date: 10/28/2025

Reference Information

CVE: CVE-2025-12419

IAVA: 2025-A-0893