{"cve":"CVE-2017-18909","nvd":{"published":"2020-06-19T19:15:11.827","modified":"2026-06-17T01:13:48.750","status":"Modified","description":"An issue was discovered in Mattermost Server before 3.9.0 when SAML is used. Encryption and signature verification are not mandatory.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5},"cwes":["CWE-295"],"references":["https://mattermost.com/security-updates/","https://mattermost.com/security-updates/"],"products":["mattermost:mattermost_server"],"source":"nvd","synced_at":"2026-10-19T21:05:42.039641217+00:00"},"epss":{"cve":"CVE-2017-18909","score":0.00656,"percentile":0.51422,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-r6j5-fqx9-7qv9","url":"https://osv.dev/vulnerability/GHSA-r6j5-fqx9-7qv9","summary":"Mattermost Server SAML implementation does not require encryption or signature verification as default","modified":"2026-02-19T20:41:06.840451Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["<3.8.1-0.20170504181128-4f074fed0d65"],"fixed":["3.8.1-0.20170504181128-4f074fed0d65"]}]},{"id":"GO-2026-4478","url":"https://osv.dev/vulnerability/GO-2026-4478","summary":"Mattermost Server SAML implementation does not require encryption or signature verification as default in github.com/mattermost/mattermost-server","modified":"2026-02-19T20:41:06.840451Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}