CVE-2019-1258

CVE-2019-1258 is a high-severity vulnerability in Microsoft Active Directory Authentication Library with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

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. 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.

Frequently asked questions

What is CVE-2019-1258?
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.
How severe is CVE-2019-1258?
CVE-2019-1258 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-1258 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-1258?
CVE-2019-1258 primarily affects Microsoft Active Directory Authentication Library. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-1258?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-1258 published?
CVE-2019-1258 was published on 2019-08-14 and last updated on 2026-06-17.

References

Affected products (6)