CVE-2026-26304 Permission Bypass in Playbook Run Creation

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2 fail to verify runcreate permission for empty playbookId, which allows team members to create unauthorized runs via the playbook run API. Mattermost Advisory ID: MMSA-2025-00542...