Detections
Analytics

Mattermost Server 10.11.x < 10.11.20 / 11.6.x < 11.6.5 / 11.7.x < 11.7.2 Incorrect Authorization (MMSA-2026-00653)

medium Nessus Plugin ID 327419

Synopsis

The remote host is affected by an incorrect authorization vulnerability.

Description

The version of Mattermost Server installed on the remote host is affected by a vulnerability as referenced in the MMSA-2026-00653 advisory.

 - Mattermost versions 11.7.x <= 11.7.1, 11.6.x <= 11.6.4, 10.11.x <= 10.11.19 fail to restrict metric configuration changes to the playbook being saved, which allows an authenticated user with team access to alter another user's playbook metric settings via a crafted import or update request with a foreign metric ID. Mattermost Advisory ID: MMSA-2026-00653. (CVE-2026-6541)

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 10.11.20, 11.6.5, 11.7.2 / 11.8.0 or later.

See Also

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

Plugin Details

Severity: Medium

ID: 327419

File Name: mattermost_server_MMSA-2026-00653.nasl

Version: 1.1

Type: Remote

Family: CGI abuses

Published: 7/16/2026

Updated: 7/16/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 4

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:N

CVSS Score Source: CVE-2026-6541

CVSS v3

Risk Factor: Medium

Base Score: 4.3

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

Vulnerability Information

CPE: cpe:/a:mattermost:mattermost_server

Required KB Items: installed_sw/Mattermost Server

Patch Publication Date: 6/12/2026

Vulnerability Publication Date: 6/12/2026

Reference Information

CVE: CVE-2026-6541