{"cve":"CVE-2017-18906","nvd":{"published":"2020-06-19T20:15:12.147","modified":"2026-06-17T01:13:48.423","status":"Modified","description":"An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2, when Single Sign-On OAuth2 is used. An attacker could claim somebody else's account.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","score":8.1},"cwes":["CWE-287"],"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-2017-18906","score":0.00789,"percentile":0.56263,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fpcr-4rr5-hpcp","url":"https://osv.dev/vulnerability/GHSA-fpcr-4rr5-hpcp","summary":"Mattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used","modified":"2026-02-19T20:41:01.127939Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["<3.9.2-0.20170714134023-b17fca0d5ee7"],"fixed":["3.9.2-0.20170714134023-b17fca0d5ee7"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":[">=3.10.0 <3.10.2"],"fixed":["3.10.2"]}]},{"id":"GO-2026-4477","url":"https://osv.dev/vulnerability/GO-2026-4477","summary":"Mattermost Server vulnerable to user account takeover when Single Sign-On OAuth2 is used in github.com/mattermost/mattermost-server","modified":"2026-02-19T20:41:01.127939Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":[">=3.10.0+incompatible <3.10.2+incompatible"],"fixed":["3.10.2+incompatible"]}]}],"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."]}