{"id":"CVE-2017-18871","aliases":["GHSA-jc6w-8r7f-vmp5","GO-2025-4184"],"url":"https://o3.security/vulnerability/CVE-2017-18871","summary":"Mattermost Server vulnerable to Denial of Service through `@` character prefix inserted into JavaScript field names","details":"An issue was discovered in Mattermost Server before 4.5.0, 4.4.5, 4.3.4, and 4.2.2. It allows attackers to cause a denial of service (application crash) via an @ character before a JavaScript field name.","published":"2020-06-19T17:15:11.867Z","modified":"2026-08-27T08:19:02.045711Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.01114,"percentile":0.6437,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.2.2"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.3.4"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.4.5"},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"4.5.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T08:19:02.045711Z"}}