{"id":"CVE-2018-21257","aliases":["EUVD-2018-13772","GHSA-qg8w-6226-7h2q"],"status":"published","title":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended...","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.00814,"percentile":0.57298,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-862"],"published":"2020-06-19T16:51:47Z","modified":"2026-10-24T10:30:22Z","products":[{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates/","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-21257"},{"url":"https://github.com/advisories/GHSA-qg8w-6226-7h2q"}],"sources":{"cve":[{"id":"CVE-2018-21257","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","status":"published","published":"2020-06-19T16:51:47Z","modified":"2024-08-05T12:26:39.573Z","updated_at":"2026-11-02T14:35:02.289647Z"}],"euvd":[{"id":"EUVD-2018-13772","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","status":"published","published":"2020-06-19T16:51:47Z","modified":"2024-08-05T12:26:39Z","updated_at":"2026-11-03T02:39:27.875919Z"}],"ghsa":[{"id":"GHSA-qg8w-6226-7h2q","title":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended...","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","status":"published","published":"2022-05-24T17:21:09Z","modified":"2023-01-29T05:03:05Z","updated_at":"2026-11-02T14:45:14.198561Z"}],"nvd":[{"id":"CVE-2018-21257","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","status":"published","published":"2020-06-19T17:15:12.74Z","modified":"2026-06-17T01:54:29.01Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:05:00.03074Z"}],"osv":[{"id":"CVE-2018-21257","description":"An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for setting a channel header) via the Channel header slash command API.","status":"published","published":"2020-06-19T17:15:12.74Z","modified":"2026-10-24T10:30:22.670250304Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:09.145458Z"}]}}