{"id":"CVE-2019-1258","aliases":["EUVD-2019-0644","GHSA-xc6x-cq47-9chw"],"status":"published","title":"Azure Active Directory Authentication Library Elevation of Privilege Vulnerability","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens. This vulnerability allows an authenticated attacker to perform actions in context of another user.\nThe authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens.\nThis security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.","severity":{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.03799,"percentile":0.90075,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"published":"2019-08-14T20:55:06Z","modified":"2026-10-24T10:30:42Z","fixes":[{"ecosystem":"NuGet","package":"microsoft.identitymodel.clients.activedirectory","fixed_in":["5.2.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"microsoft.identitymodel.clients.activedirectory","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"last_affected":"5.1.1"},{"fixed":"5.2.0"}]}]},{"source":"osv","ecosystem":"NuGet","package":"microsoft.identitymodel.clients.activedirectory","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.0.0"},{"fixed":"5.2.0"}]}],"versions":["5.0.1-preview","5.0.2-preview","5.0.3-preview","5.0.5","5.1.0","5.1.1"]}],"products":[{"vendor":"microsoft","product":"active_directory_authentication_library"},{"vendor":"microsoft","product":"adal.net"},{"vendor":"microsoft","product":"nuget"},{"vendor":"microsoft","product":"nuget 5.2.0"}],"references":[{"url":"https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1258","tags":["x_refsource_MISC","x_transferred","Patch","Vendor Advisory","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2019-1258","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-xc6x-cq47-9chw"},{"url":"https://github.com/AzureAD/azure-activedirectory-library-for-dotnet","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2019-1258","title":"Azure Active Directory Authentication Library Elevation of Privilege Vulnerability","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens. This vulnerability allows an authenticated attacker to perform actions in context of another user.\nThe authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens.\nThis security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.","status":"published","published":"2019-08-14T20:55:06Z","modified":"2024-08-04T18:13:29.539Z","updated_at":"2026-11-02T14:20:25.661187Z"}],"euvd":[{"id":"EUVD-2019-0644","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens. This vulnerability allows an authenticated attacker to perform actions in context of another user.\nThe authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens.\nThis security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.","status":"published","published":"2019-08-14T20:55:06Z","modified":"2024-08-04T18:13:29Z","updated_at":"2026-11-03T03:06:58.838317Z"}],"ghsa":[{"id":"GHSA-xc6x-cq47-9chw","title":"Vulnerability in Azure Active Directory Authentication Library","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens, aka 'Azure Active Directory Authentication Library Elevation of Privilege Vulnerability'.","status":"published","published":"2019-08-16T14:03:35Z","modified":"2024-05-31T21:10:03Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T14:37:53.025064Z"}],"nvd":[{"id":"CVE-2019-1258","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens. This vulnerability allows an authenticated attacker to perform actions in context of another user.\nThe authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens.\nThis security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.","status":"published","published":"2019-08-14T21:15:19.173Z","modified":"2026-06-17T02:28:15.33Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.5,"vector":"AV:N/AC:L/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:05:22.878504Z"}],"osv":[{"id":"CVE-2019-1258","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens. This vulnerability allows an authenticated attacker to perform actions in context of another user.\nThe authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens.\nThis security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.","status":"published","published":"2019-08-14T21:15:19.173Z","modified":"2026-10-24T10:30:42.470088068Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:10.718934Z"},{"id":"GHSA-xc6x-cq47-9chw","title":"Vulnerability in Azure Active Directory Authentication Library","description":"An elevation of privilege vulnerability exists in Azure Active Directory Authentication Library On-Behalf-Of flow, in the way the library caches tokens, aka 'Azure Active Directory Authentication Library Elevation of Privilege Vulnerability'.","status":"published","published":"2019-08-16T14:03:35Z","modified":"2024-12-06T05:28:22.115742Z","cvss":[{"version":"3.0","score":8.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:46:59.835583Z"}]}}