{"id":"CVE-2026-4055","summary":"Insufficient permission validation on cross-team playbook run creation","details":"Mattermost versions 11.5.x \u003c= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629","aliases":["GHSA-6cfr-wp44-6qmv","GO-2026-5173"],"modified":"2026-07-31T18:30:13.512305448Z","published":"2026-05-21T07:13:31.669Z","related":["openSUSE-SU-2026:21483-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4055.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"11.5.0"},{"last_affected":"11.5.1"}]}],"cna_assigner":"Mattermost","cwe_ids":["CWE-863"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4055.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4055"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"202d125afa87fe39611686850fd82590c99ca344"},{"introduced":"9f2616376582893035a7e3cb38b0fab648bba4e8"},{"fixed":"d5f29c8ebbeb04460d16d9e2635ce50deeb78428"},{"introduced":"d4f4e78835e86e2e76f76bfe797623076f5c9835"},{"fixed":"1ce2484a00c9821ee19708d2c46720e4855033a9"}],"database_specific":{"cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"10.11.0"},{"fixed":"10.11.17"},{"introduced":"11.5.0"},{"fixed":"11.5.5"},{"introduced":"11.6.0"},{"fixed":"11.6.2"}],"source":"CPE_RANGE"}}],"versions":["v10.11.15-rc1","v10.11.15","v11.5.4","v11.6.1-rc1","v11.6.1","v11.5.3","v10.11.14","v11.5.2-rc3","v11.5.2","v11.6.0","v10.11.14-rc1","v11.5.0","v11.5.2-rc2","v11.5.2-rc1","v10.11.13","v11.5.1","v10.11.13-rc1","v10.11.12","v10.11.11-rc2","v10.11.11","v10.11.11-rc1","v10.11.10","v10.11.9","v10.11.9-rc1","v10.11.8","v10.11.7","v10.11.6","v10.11.5","v10.11.4-rc3","v10.11.4","v10.11.4-rc2","v10.11.4-rc1","v10.11.3","v10.11.2-rc2","v10.11.2","v10.11.2-rc1","v10.11.1","v10.11.1-rc1","v10.11.0-rc3","v10.11.0","mattermost-redux@10.11.0","@mattermost/types@10.11.0","@mattermost/client@10.11.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-4055.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"}]}