An elevation of privilege vulnerability exists when Windows improperly handles calls to Win32k.sys, aka "Windows Win32k Elevation of Privilege Vulnerability." This affects Windows Server 2008, Windows 7, Windows Server 2008 R2.
Conclusion & alert: CVE-2018-8589 is rated Critical Active Threat (94.6/100): CVSS High severity, with high exploitation likelihood (EPSS 50.44%, 98th percentile). Core evidence: CISA KEV confirms active exploitation (added 2022-05-23) affecting Microsoft / Win32k. Unauthenticated remote administrative access may be possible. EPSS rose +4.18% over the last day, indicating growing attacker interest. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
: Microsoft Win32k Privilege Escalation Vulnerability · CISA KEV detail
: 2022-05-23
: 2022-06-13
: Apply updates per vendor instructions.
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 | 2026-04-04 | 46.26% | 50.44% | +4.18% |
| 2 | 2026-02-20 | 46.85% | 46.26% | -0.59% |
| 3 | 2026-02-18 | — | 46.85% | — |
Full EPSS history (29 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | [email protected] |
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| 7.2 | 2.0 | HIGH |
|
3.9 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_7 | — | cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:itanium:* |
| microsoft | windows_server_2008 | r2 | cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:* |
| URL | Tags |
|---|---|
| http://www.securityfocus.com/bid/105796 | Broken Link Third Party Advisory VDB Entry |
| http://www.securitytracker.com/id/1042140 | Broken Link Third Party Advisory VDB Entry |
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8589 | Patch Vendor Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-8589 | US Government Resource |