{"id":"CVE-2026-22880","aliases":["EUVD-2026-31250","GHSA-j628-rc2h-qj7g"],"status":"published","title":"Mobile SSO authentication flow allows credential theft via malicious server","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00117,"percentile":0.01708,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-352"],"published":"2026-05-21T08:22:00Z","modified":"2026-10-28T02:30:59Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_mobile"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-22880","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-j628-rc2h-qj7g"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22880.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-22880","title":"Mobile SSO authentication flow allows credential theft via malicious server","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","status":"published","published":"2026-05-21T08:22:00.182Z","modified":"2026-05-21T12:39:30.334Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T13:39:05.585774Z"}],"euvd":[{"id":"EUVD-2026-31250","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","status":"published","published":"2026-05-21T08:22:00Z","modified":"2026-05-21T12:39:30Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:21:13.357667Z"}],"ghsa":[{"id":"GHSA-j628-rc2h-qj7g","title":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to...","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","status":"published","published":"2026-05-21T09:32:11Z","modified":"2026-05-21T09:32:16Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T15:08:15.106873Z"}],"nvd":[{"id":"CVE-2026-22880","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","status":"published","published":"2026-05-21T09:16:26.51Z","modified":"2026-08-06T15:42:06.99Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T14:12:19.752984Z"}],"osv":[{"id":"CVE-2026-22880","title":"Mobile SSO authentication flow allows credential theft via malicious server","description":"Mattermost Mobile Apps versions \u003c=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564","status":"published","published":"2026-05-21T08:22:00.182Z","modified":"2026-10-28T02:30:59.748201801Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-352"],"updated_at":"2026-11-02T15:44:58.749922Z"}]}}