CVE-2026-6343 MEDIUM

CVE-2026-6343: Mattermost Playbooks Plugin fails to enforce view permissions in list endpoints, allowing unauthorized access to public playbooks

Vendor Mattermost
Product Mattermost
Weakness CWE-863 · Incorrect authorization
Published May 18, 2026
Last update May 18, 2026

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

May 18, 2026 CVE published
May 18, 2026 Record updated