Cyber Resilience

CVE-2019-0859

HighCISA KEVActive ExploitationEUVD Exploited

Published: 09 April 2019

Published
09 April 2019
Modified
29 October 2025
KEV Added
03 November 2021
Patch
CVSS Score v3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1064 93.5th percentile
Risk Priority 42 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2019-0859 is a high-severity an unspecified weakness vulnerability in Microsoft Windows 10 1709. Its CVSS base score is 7.8 (High).

Operationally, ranked in the top 6.5% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and SI-16 (Memory Protection).

Deeper analysis

The vulnerability CVE-2019-0859 is an elevation of privilege issue affecting the Win32k component of Windows, where the software fails to properly handle objects in memory. This flaw is distinct from related issues tracked as CVE-2019-0685 and CVE-2019-0803.

A local attacker with existing low-privileged access can exploit the weakness without user interaction to obtain higher privileges on the system, resulting in full compromise of confidentiality, integrity, and availability.

Microsoft provides mitigation details and patches via its security advisory at portal.msrc.microsoft.com, while CISA lists the vulnerability in its known exploited vulnerabilities catalog, confirming real-world exploitation activity.

EU & UK References

Vulnerability details

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory, aka 'Win32k Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0685, CVE-2019-0803.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

microsoft
windows 10 1507
all versions
microsoft
windows 10 1607
all versions
microsoft
windows 10 1703
all versions
microsoft
windows 10 1709
all versions
microsoft
windows 10 1803
all versions
microsoft
windows 10 1809
all versions
microsoft
windows 7
all versions
microsoft
windows 8.1
all versions
microsoft
windows rt 8.1
all versions
microsoft
windows server 1709
all versions
+5 more product configuration(s) — see NVD for full list

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly counters the EoP goal of CVE-2019-0859 by restricting processes to the minimum privileges needed, blocking the Win32k memory-object flaw from yielding SYSTEM-level access.

prevent

Addresses the root cause—improper memory-object handling inside Win32k—by enforcing OS-level memory protections that prevent corruption-based privilege escalation.

prevent

Requires timely application of the vendor patch that eliminates the Win32k memory-handling flaw listed in the CISA KEV catalog.

References