{"id":"CVE-2017-18889","details":"An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. An attacker could create fictive system-message posts via webhooks and slash commands, in the v3 or v4 REST API.","aliases":["GHSA-jp57-4x34-5v94","GO-2025-4201"],"modified":"2026-03-11T07:47:39.714570569Z","published":"2020-06-19T19:15:10.653Z","related":["SUSE-SU-2026:0037-1"],"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost-server","events":[{"introduced":"0"},{"fixed":"61d6a7434b18612c52d0d6b7565032065262e096"},{"introduced":"a5ce36d0882ae1b4b409a7b68233bf89591a5f95"},{"fixed":"c0aafbcdc221970054869b6c03db77c1dcc63289"}]}],"versions":["v4.2.0","v4.2.0-rc4"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2017-18889.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"}]}