Microsoft Win32k Privilege Escalation Vulnerability

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'.

CheckOps priority index

7.8/10 Patch within 7 days

Severity7.8

Probability7.4

Exploitation4/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 74.4% higher than 99.5% of CVEs

CVSS 3.1 7.8 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:

Exploited for 1,758 days 10 Jan 2022

CISA due date 10 Jul 2022 for US federal agencies

Exploitation probability EPSS · FIRST

EPSS probability (%)Percentile among all CVEs

Exploitation signals 4 / 5

KEV catalog (CISA)10 Jan 2022
Exploited in EUVD (ENISA)10 Jan 2022
Used by ransomwareyes
EPSS above 10 %74.4%
No account, over the networkno

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: Apply updates per vendor instructions.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Affected products

WindowsWindows ServerWin32k

Affected versions

8.1 for x64-based systems
2008 R2 for Itanium-Based Systems Service Pack 1
2012 R2 (Core installation)
10 Version 1607 for 32-bit Systems
10 Version 1607 for x64-based Systems
2012 R2
2008 R2 for x64-based Systems Service Pack 1 (Core installation)
10 for 32-bit Systems
2012 (Core installation)
8.1 for 32-bit systems
2008 for x64-based Systems Service Pack 2 (Core installation)
2008 for x64-based Systems Service Pack 2

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

10 Dec 2019
Published
10 Jan 2022
Exploitation reported (ENISA)
10 Jan 2022
Added to the KEV catalog
10 Jul 2022
CISA remediation due date
06 Oct 2026
EPSS peak: 74.4%

References

Other exploited vulnerabilities from the same vendor

CVE-2026-96951Microsoft Windows Command Injection Vulnerability
5.6 · Actively exploited
CVE-2026-65660Microsoft SharePoint Code Injection Vulnerability
5.0 · Actively exploited
CVE-2026-85880Microsoft Windows Heap-Based Buffer Overflow Vulnerability
4.3 · Actively exploited
CVE-2026-81963Microsoft Windows Link Following Vulnerability
4.3 · Actively exploited
CVE-2019-1068Microsoft SQL Server Remote Code Execution Vulnerability
7.0 · Actively exploited
CVE-2026-69836Microsoft Entra
5.3 · Actively exploited