CVE-2026-33839 Details
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.
A race condition vulnerability has been identified in the Windows Win32K component, specifically within the Graphics (GRFX) subsystem. This vulnerability allows an authorized attacker to locally elevate privileges. The issue arises from improper synchronization in concurrent execution using shared resources, creating a race condition that can be exploited to gain higher privileges.
Users can apply the security update KB5087538 for Windows Server 2019, KB5087544 for various Windows 10 versions, KB5089548 for Windows 11 versions 26H1, and KB5087420 for Windows 11 version 23H2. For Windows Server 2022, the security update KB5087545 is available. Instructions for downloading these security updates can be found on the Microsoft Update Catalog.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 13, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33839 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft windows 10 1809 | < 10.0.17763.8755 |
CPE
Remediation
| |
| microsoft windows 10 21h2 | < 10.0.19044.7291 |
CPE
Remediation
| |
| microsoft windows 10 22h2 | < 10.0.19045.7291 |
CPE
Remediation
| |
| microsoft windows 11 23h2 | < 10.0.22631.7079 |
CPE
Remediation
| |
| microsoft windows 11 24h2 | < 10.0.26100.8390 |
CPE
Remediation
| |
| microsoft windows 11 25h2 | < 10.0.26200.8390 |
CPE
Remediation
| |
| microsoft windows 11 26h1 | < 10.0.28000.2113 |
CPE
Remediation
| |
| microsoft windows server 2019 | < 10.0.17763.8755 |
CPE
Remediation
| |
| microsoft windows server 2022 | < 10.0.20348.5074 |
CPE
Remediation
| |
| microsoft windows server 2022 23h2 | < 10.0.25398.2330 |
CPE
Remediation
| |
| microsoft windows server 2025 | < 10.0.26100.32772 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 14, 2026 | Initial Analysis | [email protected] |
| May 12, 2026 | New CVE Received | [email protected] |