{"id":"CVE-2026-9597","aliases":["EUVD-2026-43315","GHSA-42ff-p8fr-h5jr"],"status":"published","title":"Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","severity":{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.0023,"percentile":0.13951,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-305"],"published":"2026-07-13T08:17:36Z","modified":"2026-10-28T02:31:01Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_server"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9597","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-42ff-p8fr-h5jr"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9597.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-9597","title":"Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","status":"published","published":"2026-07-13T08:17:36.717Z","modified":"2026-07-13T13:55:15.448Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T13:42:26.790871Z"}],"euvd":[{"id":"EUVD-2026-43315","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","status":"published","published":"2026-07-13T08:17:36Z","modified":"2026-07-13T13:55:15Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:01.93893Z"}],"ghsa":[{"id":"GHSA-42ff-p8fr-h5jr","title":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is...","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","status":"published","published":"2026-07-13T09:31:43Z","modified":"2026-07-13T09:31:51Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T15:09:24.680615Z"}],"nvd":[{"id":"CVE-2026-9597","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","status":"published","published":"2026-07-13T09:16:25.137Z","modified":"2026-07-13T20:53:34.213Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T14:12:28.771746Z"}],"osv":[{"id":"CVE-2026-9597","title":"Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint","description":"Mattermost versions 11.7.x \u003c= 11.7.2, 11.6.x \u003c= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681","status":"published","published":"2026-07-13T08:17:36.717Z","modified":"2026-10-28T02:31:01.105303128Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-305"],"updated_at":"2026-11-02T15:45:21.262447Z"}]}}