{"id":"CVE-2026-16453","revision":null,"records":[{"revision":"6469c92bd55c485d8a1c39acaec298d2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-16453","aliases":[],"title":"Mattermost SAML RelayState forgery allows unauthorized team membership","description":"Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to verify the integrity of the SAML RelayState POST parameter which allows an authenticated SAML user to join any team, including invite-only teams, via forging the team_id or invite_id fields in the RelayState.. 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