{"id":"CVE-2017-18879","aliases":["GHSA-498j-wxww-j897","GO-2025-4189"],"url":"https://o3.security/vulnerability/CVE-2017-18879","summary":"Mattermost Server is vulnerable to XSS through author_link field in Slack attachments","details":"An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. XSS could occur via the author_link field of a Slack attachment.","published":"2020-06-19T19:15:10.077Z","modified":"2026-07-31T18:30:06.496886129Z","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":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.1.2"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.2.1"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.3.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:30:06.496886129Z"}}