{"id":"CVE-2023-49278","aliases":["EUVD-2023-3155","GHSA-7x74-h8cw-qhxq"],"status":"published","title":"Umbraco CMS brute force exploit can be used to collect valid usernames","description":"Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.4, a brute force exploit can be used to collect valid usernames. Versions 8.18.10, 10.8.1, and 12.3.4 contain a patch for this issue.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.005,"percentile":0.43339,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-200","CWE-307"],"published":"2023-12-12T19:14:02Z","modified":"2026-10-28T02:30:33Z","fixes":[{"ecosystem":"NuGet","package":"Umbraco.CMS","fixed_in":["8.18.10","10.8.1","12.3.4"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"8.0.0"},{"fixed":"8.18.10"}]}]},{"source":"ghsa","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"9.0.0"},{"fixed":"10.8.1"}]}]},{"source":"ghsa","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.0.0"},{"fixed":"12.3.4"}]}]},{"source":"osv","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"8.0.0"},{"fixed":"8.18.10"}]}]},{"source":"osv","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"9.0.0"},{"fixed":"10.8.1"}]}],"versions":["10.0.0","10.0.0-rc1","10.0.0-rc2","10.0.0-rc3","10.0.0-rc4","10.0.0-rc5","10.0.1","10.1.0","10.1.0-rc","10.1.0-rc2","10.1.1","10.2.0","10.2.0-rc","10.2.1","10.3.0","10.3.0-rc","10.3.1","10.3.2","10.4.0","10.4.0-rc","10.4.1","10.4.2","10.5.0","10.5.0-rc","10.5.1","10.6.0","10.6.0-rc","10.6.1","10.7.0","10.7.0-rc","10.8.0","10.8.0-rc","9.0.0","9.0.1","9.1.0","9.1.0-rc","9.1.1","9.1.2","9.2.0","9.2.0-rc","9.3.0","9.3.0-rc","9.3.1","9.4.0","9.4.0-rc","9.4.1","9.4.2","9.4.3","9.5.0","9.5.0-rc","9.5.0-rc2","9.5.0-rc3","9.5.1","9.5.2","9.5.3","9.5.4"]},{"source":"osv","ecosystem":"NuGet","package":"Umbraco.CMS","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"11.0.0"},{"fixed":"12.3.4"}]}],"versions":["11.0.0","11.1.0","11.1.0-rc","11.2.0","11.2.0-rc","11.2.1","11.2.2","11.3.0","11.3.0-rc","11.3.1","11.4.0","11.4.0-rc","11.4.1","11.4.2","11.5.0","11.5.0-rc","12.0.0","12.0.0-rc1","12.0.0-rc2","12.0.0-rc3","12.0.0-rc4","12.0.0-rc5","12.0.1","12.1.0","12.1.0-rc","12.1.1","12.1.2","12.2.0","12.2.0-rc","12.3.0","12.3.0-rc","12.3.1","12.3.2","12.3.3"]}],"products":[{"vendor":"umbraco","product":"umbraco-cms"},{"vendor":"umbraco","product":"umbraco_cms"}],"references":[{"url":"https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-7x74-h8cw-qhxq","tags":["x_refsource_CONFIRM","x_transferred","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-49278","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7x74-h8cw-qhxq"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/49xxx/CVE-2023-49278.json","tags":["advisory"]},{"url":"https://github.com/umbraco/Umbraco-CMS","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-49278","title":"Umbraco CMS brute force exploit can be used to collect valid usernames","description":"Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.4, a brute force exploit can be used to collect valid usernames. Versions 8.18.10, 10.8.1, and 12.3.4 contain a patch for this issue.","status":"published","published":"2023-12-12T19:14:02.789Z","modified":"2024-10-08T14:33:55.652Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-200","CWE-307"],"updated_at":"2026-11-02T14:35:12.998024Z"}],"euvd":[{"id":"EUVD-2023-3155","description":"Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.4, a brute force exploit can be used to collect valid usernames. Versions 8.18.10, 10.8.1, and 12.3.4 contain a patch for this issue.","status":"published","published":"2023-12-12T19:14:02Z","modified":"2024-10-08T14:33:55Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T00:27:45.808193Z"}],"ghsa":[{"id":"GHSA-7x74-h8cw-qhxq","title":" Brute force exploit can be used to collect valid usernames","description":"#### Impact\nA brute force exploit that can be used to collect valid usernames is possible.\n\n#### Explanation of the vulnerability \nIt's a brute force exploit that can be used to collect valid usernames by using the “forgot password” function when trying to log into the Backoffice.\nIf the username/email is known, it is easier to find the corresponding password.\nIf an email address that was already used and registered by a user, is provided as an input, the server internal processing time takes longer.\nIf the email address does not exist in the database of the registered users, the server would respond immediately.","status":"published","published":"2023-12-13T13:27:06Z","modified":"2024-01-12T16:27:50Z","cvss":[{"version":"3.1","score":0,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N","level":"none"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T14:37:30.812736Z"}],"nvd":[{"id":"CVE-2023-49278","description":"Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.4, a brute force exploit can be used to collect valid usernames. Versions 8.18.10, 10.8.1, and 12.3.4 contain a patch for this issue.","status":"published","published":"2023-12-12T20:15:08.19Z","modified":"2026-06-17T06:35:44.937Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-200","CWE-307"],"updated_at":"2026-11-02T14:08:54.696438Z"}],"osv":[{"id":"CVE-2023-49278","title":"Umbraco CMS brute force exploit can be used to collect valid usernames","description":"Umbraco is an ASP.NET content management system (CMS). Starting in version 8.0.0 and prior to versions 8.18.10, 10.8.1, and 12.3.4, a brute force exploit can be used to collect valid usernames. Versions 8.18.10, 10.8.1, and 12.3.4 contain a patch for this issue.","status":"published","published":"2023-12-12T19:14:02.789Z","modified":"2026-10-28T02:30:33.045549339Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-200","CWE-307"],"updated_at":"2026-11-02T15:44:34.72355Z"},{"id":"GHSA-7x74-h8cw-qhxq","title":" Brute force exploit can be used to collect valid usernames","description":"#### Impact\nA brute force exploit that can be used to collect valid usernames is possible.\n\n#### Explanation of the vulnerability \nIt's a brute force exploit that can be used to collect valid usernames by using the “forgot password” function when trying to log into the Backoffice.\nIf the username/email is known, it is easier to find the corresponding password.\nIf an email address that was already used and registered by a user, is provided as an input, the server internal processing time takes longer.\nIf the email address does not exist in the database of the registered users, the server would respond immediately.","status":"published","published":"2023-12-13T13:27:06Z","modified":"2026-09-10T03:50:01.782735694Z","cvss":[{"version":"3.1","score":0,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N","level":"none"}],"cwes":["CWE-200"],"updated_at":"2026-11-02T15:46:41.732368Z"}]}}