Mattermost Server 10.5.x < 10.5.12 / 10.11.x 10.11.4 / 10.12.x < 10.12.1 / 11.0.0 Multiple Vulnerabilities (MMSA-2025-00541, MMSA-2025-00492)

medium Nessus Plugin ID 275844

Synopsis

The remote host is missing a security update.

Description

The version of Mattermost Server installed on the remote host is affected by multiple vulnerabilities as referenced in the MMSA-2025-00541, MMSA-2025-00492 advisory.

- Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to sanitize user data which allows system administrators to access password hashes and MFA secrets via the POST /api/v4/users/{user_id}/email/verify/member endpoint. (CVE-2025-11794)

- Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL. (CVE-2025-55073)

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

Solution

Upgrade to Mattermost Server version 10.5.12, 10.11.4, 10.12.1, 11.0.0 or later.

See Also

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

Plugin Details

Severity: Medium

ID: 275844

File Name: mattermost_server_MMSA-2025-00541_MMSA-2025-00492.nasl

Version: 1.2

Type: remote

Family: CGI abuses

Published: 11/20/2025

Updated: 11/21/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5.5

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

CVSS Score Source: CVE-2025-11794

CVSS v3

Risk Factor: Medium

Base Score: 5.4

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

Vulnerability Information

CPE: cpe:/a:mattermost:mattermost_server

Required KB Items: installed_sw/Mattermost Server

Patch Publication Date: 11/14/2025

Vulnerability Publication Date: 11/14/2025

Reference Information

CVE: CVE-2025-11794, CVE-2025-55073

IAVA: 2025-A-0866