CVE-2019-1258
Azure Active Directory Authentication Library Elevation of Privilege Vulnerability
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. The authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens. This security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
8.8
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. The authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens. This security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.
- Record
CVE-2019-1258- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Updated
- 2026-11-02
CVE List No score
Azure Active Directory Authentication Library Elevation of Privilege Vulnerability
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. The authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens. This security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.
- Record
CVE-2019-1258- Updated
- 2026-11-02
EUVDEUVD-2019-0644 No score
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. The authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens. This security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.
- Record
EUVD-2019-0644- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-xc6x-cq47-9chw
8.8
Vulnerability in Azure Active Directory Authentication Library
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'.
- Record
GHSA-xc6x-cq47-9chw- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSV
8.8
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. The authenticated attacker can exploit this vulneraiblity by accessing a service configured for On-Behalf-Of flow that assigns incorrect tokens. This security update addresses the vulnerability by removing fallback cache look-up for On-Behalf-Of scenarios.
- Record
CVE-2019-1258- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-xc6x-cq47-9chw
8.8
Vulnerability in Azure Active Directory Authentication Library
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'.
- Record
GHSA-xc6x-cq47-9chw- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
microsoft.identitymodel.clients.activedirectoryNuGet |
5.0.0 to 5.1.1 | 5.2.0 |
microsoft.identitymodel.clients.activedirectoryNuGet |
5.0.0 up to 5.2.0, plus listed versions 5.0.1-preview5.0.2-preview5.0.3-preview5.0.55.1.05.1.1 |
5.2.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-1258 is a high vulnerability (CVSS 8.8) in Microsoft Active Directory Authentication Library, published August 14, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.80%, the 90th percentile. Fixed in microsoft.identitymodel.clients.activedirectory 5.2.0.