{"id":"CVE-2026-16048","summary":"Channel member roles accept out-of-scope roles","details":"Mattermost versions 11.8.x \u003c= 11.8.2, 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles which allows a channel administrator to gain additional channel permissions via the channel member roles API.. Mattermost Advisory ID: MMSA-2026-00697","modified":"2026-08-20T03:54:12.190464369Z","published":"2026-08-17T14:22:43.940Z","database_specific":{"unresolved_ranges":[{"extracted_events":[{"introduced":"11.8.0"},{"last_affected":"11.8.2"},{"introduced":"11.7.0"},{"last_affected":"11.7.6"},{"introduced":"10.11.0"},{"last_affected":"10.11.21"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"Mattermost","cwe_ids":["CWE-863"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16048.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16048.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16048"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"d6dbfe06f8abbe0d9d57cf47dc322042a826eb42"},{"introduced":"a9e574a82633915f22071f0d7ca2b006f249ec2a"},{"fixed":"2045acd92c40353abfc5ffff8ae1e0dd9d2e6737"},{"introduced":"e8bd2b8a871cbeff6943bead62328478118188df"},{"fixed":"af5de44c451ca732ed2cfab29f0df0562d5e6e21"}],"database_specific":{"cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"10.11.0"},{"fixed":"10.11.22"},{"introduced":"11.7.0"},{"fixed":"11.7.7"},{"introduced":"11.8.0"},{"fixed":"11.8.3"}],"source":"CPE_RANGE"}}],"versions":["v10.11.21","v11.7.6","v11.8.2","v11.7.5-rc1","v11.7.5","v11.8.1","v11.7.4","v11.7.3","v10.11.20","v11.8.0-rc5","v11.8.0","mattermost-redux@11.8.0","@mattermost/types@11.8.0","@mattermost/shared@11.8.0","@mattermost/client@11.8.0","v10.11.19","v10.11.19-rc1","v11.7.2","v10.11.18","v11.7.1","v10.11.17","v10.11.16","v11.7.0","mattermost-redux@11.7.0","@mattermost/types@11.7.0","@mattermost/shared@11.7.0","@mattermost/client@11.7.0","v10.11.15-rc1","v10.11.15","v10.11.14","v10.11.14-rc1","v10.11.13","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-2026-16048.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L"}]}