CVE-2023-49874: Mattermost Server

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

Mattermost fails to check whether a user is a guest when updating the tasks of a private playbook run allowing a guest to update the tasks of a private playbook run if they know the run ID.

Affected products

• Mattermost Mattermost Server: up to and including 7.8.14; from 8.0.0, up to and including 8.1.5; from 9.0.0, up to and including 9.0.3; from 9.1.1, up to and including 9.1.2; from 9.2.0, up to and including 9.2.1

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