CVE-2023-6727: Mattermost Server

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Mattermost fails to perform correct authorization checks when creating a playbook action, allowing users without access to the playbook to create playbook actions. If the playbook action created is to post a message in a channel based on specific keywords in a post, some playbook information, like the name, can be leaked. 

Affected products

• Mattermost Mattermost Server: up to and including 8.1.5; from 9.2.0, up to and including 9.2.1

Published 2023-12-12. Last modified 2026-06-17.