SYSTEM privilege escalation via Win32K resource race
Published May 12, 2026 · Updated May 12, 2026
A race condition in Microsoft Windows Win32K-GRFX allows local users with low privileges to gain SYSTEM access through local execution. Win32K-GRFX improperly synchronizes concurrent access to a shared graphics resource, producing a use-after-free condition. Successful exploitation requires local low-privilege access and winning the race; it grants SYSTEM privileges with no user interaction.
Summary
What happened
A race condition in Microsoft Windows Win32K-GRFX allows local users with low privileges to gain SYSTEM access through local execution. Win32K-GRFX improperly synchronizes concurrent access to a shared graphics resource, producing a use-after-free condition. Successful exploitation requires local low-privilege access and winning the race; it grants SYSTEM privileges with no user interaction.
The record
- CVE
- CVE-2026-34331
- Published
- May 12, 2026
- Updated
- May 12, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-362, CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 12, 2026CVE publishedPublication date reported by the CVE source.
- May 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8755
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo