CVE-2026-6343
Received Received - Intake
Path Traversal in Mattermost Playbooks

Publication date: 2026-05-18

Last updated on: 2026-05-18

Assigner: Mattermost, Inc.

Description
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
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-05-18
Last Modified
2026-05-18
Generated
2026-06-10
AI Q&A
2026-05-18
EPSS Evaluated
2026-06-08
NVD
CVE-2026-6343
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
mattermost mattermost_server From 10.11.0 (inc) to 10.11.14 (exc)
mattermost mattermost_server From 11.4.0 (inc) to 11.4.4 (exc)
mattermost mattermost_server From 11.5.0 (inc) to 11.5.2 (exc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-863 The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

This vulnerability affects certain versions of Mattermost (11.5.x <= 11.5.1, 10.11.x <= 10.11.13, and 11.4.x <= 11.4.3) where the system fails to properly check public/private permissions.

Because of this failure, members who do not have the required permissions can still access public playbooks through the /get endpoint.

Impact Analysis

The impact of this vulnerability is that unauthorized users can access public playbooks that they should not have permission to view.

This could lead to unintended disclosure of information contained in those playbooks, potentially exposing sensitive operational procedures or data.

The CVSS score of 4.3 indicates a low to medium severity impact, specifically a low confidentiality impact without affecting integrity or availability.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade Mattermost to a version later than 11.5.1 for the 11.5.x branch, later than 10.11.13 for the 10.11.x branch, or later than 11.4.3 for the 11.4.x branch, as these versions fix the permission checking issue allowing unauthorized access to public playbooks.

Additionally, stay informed about security updates by subscribing to Mattermost's Security Bulletin and regularly check their security updates page.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-6343. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart