Detections
Analytics

Mattermost Server 10.11.x <= 10.11.9 / 11.1.x <= 11.1.2 / 11.2.x <= 11.2.1 Improper Access Control (MMSA-2025-00550)

medium Nessus Plugin ID 299395

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-2025-00550 advisory.

 - Mattermost versions 10.11.x <= 10.11.9, 11.1.x <= 11.1.2, and 11.2.x <= 11.2.1 fail to properly validate channel permissions when using the Jira plugin. This allows an authenticated user to access attachments and content from posts in channels they don't have permission to view by creating a Jira issue with an inaccessible post ID. (CVE-2026-22892)

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 10.11.10, 11.1.3, 11.2.2, 11.3.0 or later.

See Also

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

Plugin Details

Severity: Medium

ID: 299395

File Name: mattermost_server_MMSA-2025-00550.nasl

Version: 1.2

Type: remote

Family: CGI abuses

Published: 2/18/2026

Updated: 2/19/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.9

CVSS v2

Risk Factor: Medium

Base Score: 4

Temporal Score: 3

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

CVSS Score Source: CVE-2026-22892

CVSS v3

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.8

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:mattermost:mattermost_server

Required KB Items: installed_sw/Mattermost Server

Exploit Ease: No known exploits are available

Patch Publication Date: 1/15/2026

Vulnerability Publication Date: 1/15/2026

Reference Information

CVE: CVE-2026-22892