{"id":"CVE-2026-1628","aliases":["EUVD-2026-9174","GHSA-4q28-37qp-xh4g"],"status":"published","title":"Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","severity":{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00162,"percentile":0.05442,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-829"],"published":"2026-03-02T13:24:21Z","modified":"2026-10-28T02:30:48Z","products":[{"vendor":"mattermost","product":"mattermost"},{"vendor":"mattermost","product":"mattermost_desktop"}],"references":[{"url":"https://mattermost.com/security-updates","tags":["vendor-advisory","Vendor Advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-1628","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4q28-37qp-xh4g"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/1xxx/CVE-2026-1628.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-1628","title":"Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","status":"published","published":"2026-03-02T13:24:21.391Z","modified":"2026-03-02T14:58:30.546Z","cvss":[{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-829"],"updated_at":"2026-11-02T14:20:01.271368Z"}],"euvd":[{"id":"EUVD-2026-9174","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","status":"published","published":"2026-03-02T13:24:21Z","modified":"2026-03-02T14:58:30Z","cvss":[{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T19:48:13.147525Z"}],"ghsa":[{"id":"GHSA-4q28-37qp-xh4g","title":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to...","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","status":"published","published":"2026-03-02T15:31:24Z","modified":"2026-03-02T15:31:30Z","cvss":[{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-829"],"updated_at":"2026-11-02T15:06:25.269236Z"}],"nvd":[{"id":"CVE-2026-1628","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","status":"published","published":"2026-03-02T14:16:23.223Z","modified":"2026-06-17T10:16:13.057Z","cvss":[{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-829"],"updated_at":"2026-11-02T14:12:07.420927Z"}],"osv":[{"id":"CVE-2026-1628","title":"Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.","description":"Mattermost Desktop App versions \u003c=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596","status":"published","published":"2026-03-02T13:24:21.391Z","modified":"2026-10-28T02:30:48.403108264Z","cvss":[{"version":"3.1","score":4.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-829"],"updated_at":"2026-11-02T15:44:57.682091Z"}]}}