Mattermost Server 9.11.x < 9.11.18 / 10.5.x < 10.5.9 / 10.11.0 Authorization Bypass (MMSA-2025-00502)

medium Nessus Plugin ID 266221

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-2025-00502 advisory.

- Mattermost versions 10.5.x <= 10.5.9 and 9.11.x <= 9.11.17 fail to properly validate access controls which allows any authenticated user to download sensitive files via board file download endpoint using UUID enumeration (CVE-2025-9081)

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 9.11.18 / 10.5.9 / 10.11.0 or later.

See Also

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

Plugin Details

Severity: Medium

ID: 266221

File Name: mattermost_server_MMSA-2025-00502.nasl

Version: 1.1

Type: remote

Family: CGI abuses

Published: 9/30/2025

Updated: 9/30/2025

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 6.8

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

CVSS Score Source: CVE-2025-9081

CVSS v3

Risk Factor: Medium

Base Score: 6.5

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

Vulnerability Information

CPE: cpe:/a:mattermost:mattermost_server

Required KB Items: installed_sw/Mattermost Server

Patch Publication Date: 9/15/2025

Vulnerability Publication Date: 9/15/2025

Reference Information

CVE: CVE-2025-9081

IAVA: 2025-A-0695