{"id":"CVE-2017-18907","aliases":["GHSA-42x9-rr3c-gr59","GO-2026-4459"],"url":"https://o3.security/vulnerability/CVE-2017-18907","summary":"Mattermost Server vulnerable to XSS through channel headers","details":"An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2. XSS could occur via a channel header.","published":"2020-06-19T20:15:12.197Z","modified":"2026-07-31T18:31:38.775179114Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":{"score":0.00685,"percentile":0.49543,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"3.9.2-0.20170714014920-312269ad0bd1"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"3.10.2"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:31:38.775179114Z"}}