{"id":"CVE-2026-4286","aliases":["GHSA-gvg4-jhmr-6j23","GO-2026-5404"],"url":"https://o3.security/vulnerability/CVE-2026-4286","summary":"Playbooks Plugin fails to validate team transfers, allowing unauthorized removal of member access via playbook update","details":"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","published":"2026-05-18T08:07:06.829Z","modified":"2026-08-12T03:51:36.934286917Z","cvss":{"score":3.1,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"},"epss":{"score":0.00143,"percentile":0.0413,"asOf":"2026-08-14"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","fixedVersion":"11.5.2"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","fixedVersion":"10.11.14"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-plugin-playbooks","fixedVersion":"1.41.1-0.20260213020129-e1d6ec2c94e6"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4286.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4286"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:36.934286917Z"}}