How severe is CVE-2019-0859?

CVE-2019-0859 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2019-0859?

CVE-2019-0859 affects the following products: microsoft windows 7, microsoft windows 8.1, microsoft windows 10 1507, microsoft windows 10 1607, microsoft windows 10 1703, microsoft windows 10 1709, microsoft windows 10 1803, microsoft windows 10 1809, and 7 more.

How do I patch CVE-2019-0859?

No patch has shipped for CVE-2019-0859 yet — track the microsoft windows 7 advisory for a fixed release and apply the workarounds below in the meantime.

How do I detect CVE-2019-0859 across my infrastructure?

Inventory every microsoft windows 7 deployment and check each version against the affected-products list above.

How do I mitigate CVE-2019-0859 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2019-0859 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2019-0859, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2019-0859?

CVE-2019-0859 has an EPSS (Exploit Prediction Scoring System) score of 4.2%, placing it in the 91th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2019-0859 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2019-0859 (Microsoft Win32k Privilege Escalation Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-03. The required action was: Apply updates per vendor instructions. This CVE has been used in known ransomware campaigns. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

Which products and versions are affected by CVE-2019-0859?

CVE-2019-0859 affects microsoft windows 7; microsoft windows 8.1; microsoft windows 10 1507; microsoft windows 10 1607, and 11 more product(s). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2019-0859 published, and has it been updated?

CVE-2019-0859 was published on April 9, 2019 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

CISA KEV · ACTIVELY EXPLOITED

HIGH severity

CVE-2019-0859 — Windows 7

HIGH

CVE-2019-0859 is a high-severity (CVSS 7.8) vulnerability in microsoft windows 7. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) and has been used in ransomware campaigns — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

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…

Published

Apr 9, 2019

Updated

Jun 17, 2026

Affected

15 products

Patched

See advisory

Exploits

5 known

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-05-03.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2019-0859.

EPSS Exploitation Probability

via FIRST.org ↗

4.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs91th percentile — riskier than 91% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2019-0859 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

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.

Affected Products

15 products · 27 configurations

windows 7microsoft

all

windows 8.1microsoft

all

windows 10 1507microsoft

all

windows 10 1607microsoft

all

windows 10 1703microsoft

all

windows 10 1709microsoft

all

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An elevation of privilege vulnerability exists in Windows when the Win32…

portal.msrc.microsoft.comMSApr 2019

An elevation of privilege vulnerability exists in Windows when the Win32…

portal.msrc.microsoft.comGoogle-sheetMar 2019

An elevation of privilege vulnerability exists in Windows when the Win32…

github.comGithubJun 2019

An elevation of privilege vulnerability exists in Windows when the Win32…

cisa.govCISAJul 2021

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every microsoft windows 7 deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2019-0859 yet — track the microsoft windows 7 advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

O3 Security · Runtime Protection

Is CVE-2019-0859 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works

CVE-2019-0859 — Windows 7

Exploitation Status

Actively exploited in the wild

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Description

Affected Products

Detection & mitigation playbook

Detect

Remediation status

Mitigate without a patch

Frequently Asked Questions

Is CVE-2019-0859 being exploited in your environment?