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.

Published: 2019-08-14 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2019-1258 is rated Moderate Risk (61.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.80%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2019-1258

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 10.65% 3.80% -6.85%
2 2025-11-18 11.14% 10.65% -0.49%
3 2025-03-30 11.14%

Full EPSS history (16 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-1258

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.0 6.4 [email protected]

Weakness enumeration for CVE-2019-1258

GitHub Security Advisory for CVE-2019-1258

GHSA-xc6x-cq47-9chw · Severity: high · Ecosystem: nuget — Vulnerability in Azure Active Directory Authentication Library

Affected software / configurations for CVE-2019-1258

Vendor Product Version Raw CPE
microsoft active_directory_authentication_library >= 5.0.5, < 5.2.0 cpe:2.3:a:microsoft:active_directory_authentication_library:*:*:*:*:*:.net:*:*
microsoft active_directory_authentication_library 5.0.0 cpe:2.3:a:microsoft:active_directory_authentication_library:5.0.0:preview:*:*:*:.net:*:*
microsoft active_directory_authentication_library 5.0.1 cpe:2.3:a:microsoft:active_directory_authentication_library:5.0.1:preview:*:*:*:.net:*:*
microsoft active_directory_authentication_library 5.0.2 cpe:2.3:a:microsoft:active_directory_authentication_library:5.0.2:preview:*:*:*:.net:*:*
microsoft active_directory_authentication_library 5.0.3 cpe:2.3:a:microsoft:active_directory_authentication_library:5.0.3:preview:*:*:*:.net:*:*
microsoft nuget 5.2.0 cpe:2.3:a:microsoft:nuget:5.2.0:*:*:*:*:*:*:*

References for CVE-2019-1258

cvelogic Threat Intelligence