{"id":"CVE-2017-18909","aliases":["GHSA-r6j5-fqx9-7qv9","GO-2026-4478"],"url":"https://o3.security/vulnerability/CVE-2017-18909","summary":"Mattermost Server SAML implementation does not require encryption or signature verification as default","details":"An issue was discovered in Mattermost Server before 3.9.0 when SAML is used. Encryption and signature verification are not mandatory.","published":"2020-06-19T19:15:11.827Z","modified":"2026-07-31T18:31:10.362114952Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":{"score":0.00651,"percentile":0.48223,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","fixedVersion":"3.8.1-0.20170504181128-4f074fed0d65"}],"fix":{"url":"https://github.com/mattermost/mattermost/commit/4f074fed0d653a28779ac586e418341232d43e95","label":"mattermost/mattermost@4f074fe"},"references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2017-18909"},{"type":"WEB","url":"https://github.com/mattermost/mattermost/commit/4f074fed0d653a28779ac586e418341232d43e95"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-31T18:31:10.362114952Z"}}