---
id: CVE-2026-6343
title: >-
  Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3
  fail to check public/private permissions which allows members without these
  permissions to access public playbooks via /get.
summary: >-
  Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3
  fail to check public/private permissions which allows members without these
  permissions to access public playbooks via /get.. Mattermost Advisory ID:
  MMSA-2026-0…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-863
vendor: mattermost
product: mattermost_server
affected:
  - 'mattermost_server >= 10.11.0, < 10.11.14'
  - 'mattermost_server >= 11.4.0, < 11.4.4'
  - 'mattermost_server >= 11.5.0, < 11.5.2'
patched:
  - mattermost_server 11.5.2
published: '2026-05-18'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T20:10:00.190'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6343'
references:
  - url: 'https://mattermost.com/security-updates'
    label: responsibledisclosure@mattermost.com
tags:
  - nvd
epss: 0.0027
epssPercentile: 0.17887
ingestedAt: '2026-10-14T20:53:12.300Z'
---

## Overview

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check public/private permissions which allows members without these permissions to access public playbooks via /get.. Mattermost Advisory ID: MMSA-2026-00591

## Affected

- `mattermost_server >= 10.11.0, < 10.11.14`
- `mattermost_server >= 11.4.0, < 11.4.4`
- `mattermost_server >= 11.5.0, < 11.5.2`

## Remediation

Upgrade past the affected range:

- `mattermost_server 11.5.2`