---
id: "CVE-2020-1054"
kind: "vulnerability"
aliases: ["CVE-2020-1054"]
title: "Microsoft Win32k: Microsoft Win32k Privilege Escalation Vulnerability"
severity: "high"
cvss: 7.8
epss: 0.53878
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Win32k", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "self-hosted", "windows"]
not_affected_if: ["patched-windows"]
published_at: "2020-05-21T23:15:12+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:34+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-1054", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2020-1054", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-1054", "first_seen_at": "2026-10-23T21:57:34+00:00"}]
---

# Microsoft Win32k: Microsoft Win32k Privilege Escalation Vulnerability

Microsoft Win32k, the Windows kernel-mode graphics driver, mishandles objects in memory. An attacker who already runs code on the machine can escalate to kernel-mode code execution, which gives full control of the system.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Win32k affected ? fixed ?

## Fix

Apply the Microsoft security update for CVE-2020-1054 per vendor instructions (CISA KEV required action); the sources do not name the patched build.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2020-1054
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2020-1054
- 2026-10-23T21:57:34+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2020-1054

## From the sources

An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.
To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system.
The update addresses this vulnerability by correcting how the Windows kernel-mode driver handles objects in memory.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_