{"id":"CVE-2026-16044","aliases":["EUVD-2026-60211","GHSA-496c-r634-6cgj"],"status":"published","title":"Insufficient validation of guest board admin privileges on archive import","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","severity":{"version":"3.1","score":3.9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00287,"percentile":0.214,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-863"],"published":"2026-08-17T14:26:52Z","modified":"2026-10-28T02:30:41Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16044","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-496c-r634-6cgj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16044.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-16044","title":"Insufficient validation of guest board admin privileges on archive import","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","status":"published","published":"2026-08-17T14:26:52.203Z","modified":"2026-08-17T15:25:51.74Z","cvss":[{"version":"3.1","score":3.9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:20:11.24076Z"}],"euvd":[{"id":"EUVD-2026-60211","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","status":"published","published":"2026-08-17T14:26:52Z","modified":"2026-08-17T15:25:51Z","cvss":[{"version":"3.1","score":3.9,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"low"}],"updated_at":"2026-11-02T18:01:49.335011Z"}],"ghsa":[{"id":"GHSA-496c-r634-6cgj","title":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from...","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","status":"published","published":"2026-08-17T15:30:40Z","modified":"2026-08-17T15:30:41Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:10:34.652326Z"}],"nvd":[{"id":"CVE-2026-16044","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","status":"published","published":"2026-08-17T15:16:53.857Z","modified":"2026-08-18T20:27:55.643Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:12:38.647684Z"}],"osv":[{"id":"CVE-2026-16044","title":"Insufficient validation of guest board admin privileges on archive import","description":"Mattermost versions 11.7.x \u003c= 11.7.6, 10.11.x \u003c= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672","status":"published","published":"2026-08-17T14:26:52.203Z","modified":"2026-10-28T02:30:41.377042758Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:44:57.682091Z"}]}}