CVE-2026-26304

Mattermost vulnerability CVE-2026-26304 affects Mattermost server versions 11.3.x (up to 11.3.0) and 11.2.x (up to 11.2.2). The issue is a permission check bypass in the playbook run creation path: run_create permission for an empty playbookId is not verified, enabling team members to create unau...