CVE-2026-4286 — Playbooks Plugin fails to validate team transfers, allowing unauthorized removal of member access via playbook update
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{Manage Playbook Conf…
Published: 2026-05-18 · CVSS: 3.1 · CVSS 3.1
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to check if {{team_id}} was being changed when updating playbooks, allowing users with only {{Manage Playbook Configurations}} permission to change a playbook's team, bypassing manage members restriction via PUT api. Mattermost Advisory ID: MMSA-2025-00552
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7