{"id":"CVE-2026-9597","summary":"Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint","details":"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","modified":"2026-07-16T03:48:47.555569712Z","published":"2026-07-13T08:17:36.717Z","database_specific":{"unresolved_ranges":[{"extracted_events":[{"introduced":"11.7.0"},{"last_affected":"11.7.2"},{"introduced":"11.6.0"},{"last_affected":"11.6.4"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"Mattermost","cwe_ids":["CWE-305"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9597.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/9xxx/CVE-2026-9597.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9597"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"d4f4e78835e86e2e76f76bfe797623076f5c9835"},{"fixed":"b94397a68c6129bb904dcb0ab7643b188f2717b0"},{"introduced":"a9e574a82633915f22071f0d7ca2b006f249ec2a"},{"fixed":"28b63b15f73e0ed02d0da0018e06d88c47a77c48"}],"database_specific":{"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"11.6.0"},{"fixed":"11.6.5"},{"introduced":"11.7.0"},{"fixed":"11.7.3"}]}}],"versions":["v11.6.4","v11.7.2","v11.6.3","v11.7.1","v11.6.2","v11.7.0","mattermost-redux@11.7.0","@mattermost/types@11.7.0","@mattermost/shared@11.7.0","@mattermost/client@11.7.0","v11.6.1-rc1","v11.6.1","v11.6.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-9597.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"}]}