{"id":"CVE-2017-18920","aliases":["EUVD-2017-10010","GHSA-8xcp-qq9j-65qq"],"status":"published","title":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow...","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01239,"percentile":0.69339,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"published":"2020-06-19T19:20:58Z","modified":"2026-10-24T10:30:27Z","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-2017-18920"},{"url":"https://github.com/advisories/GHSA-8xcp-qq9j-65qq"}],"sources":{"cve":[{"id":"CVE-2017-18920","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","status":"published","published":"2020-06-19T19:20:58Z","modified":"2024-08-05T21:45:24.478Z","updated_at":"2026-11-02T14:33:21.747294Z"}],"euvd":[{"id":"EUVD-2017-10010","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","status":"published","published":"2020-06-19T19:20:58Z","modified":"2024-08-05T21:45:24Z","updated_at":"2026-11-03T02:23:04.612289Z"}],"ghsa":[{"id":"GHSA-8xcp-qq9j-65qq","title":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow...","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","status":"published","published":"2022-05-24T17:21:08Z","modified":"2023-01-29T05:02:56Z","updated_at":"2026-11-02T14:45:12.348503Z"}],"nvd":[{"id":"CVE-2017-18920","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","status":"published","published":"2020-06-19T20:15:12.71Z","modified":"2026-06-17T01:13:49.96Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"2.0","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","level":"high","assessor":"primary"}],"updated_at":"2026-11-02T14:04:21.160774Z"}],"osv":[{"id":"CVE-2017-18920","description":"An issue was discovered in Mattermost Server before 3.6.2. The WebSocket feature does not follow the Same Origin Policy.","status":"published","published":"2020-06-19T20:15:12.71Z","modified":"2026-10-24T10:30:27.935041915Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:44:05.486486Z"}]}}