Win32k Elevation of Privilege Vulnerability

published 2026-05-12 5 mo ago modified 2026-08-10 2 mo ago also EUVD-2026-29589

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.

Patch / fix

fixed in 20 links 1

Microsoft Windows 10 Version 1607 10.0.14393.9140
Microsoft Windows 10 Version 1809 10.0.17763.8755
Microsoft Windows 10 Version 21H2 10.0.19044.7291
Microsoft Windows 10 Version 22H2 10.0.19045.7417
Microsoft Windows 11 version 23H2 10.0.22631.7079, 10.0.22631.7219
Microsoft Windows 11 Version 24H2 10.0.26100.8457
Microsoft Windows 11 Version 25H2 10.0.26200.8457
Microsoft Windows 11 version 26H1 10.0.28000.2113
Microsoft Windows Server 2012 6.2.9200.26079
Microsoft Windows Server 2012 (Server Core installation) 6.2.9200.26079
Microsoft Windows Server 2012 R2 6.3.9600.23181
Microsoft Windows Server 2012 R2 (Server Core installation) 6.3.9600.23181
Microsoft Windows Server 2016 10.0.14393.9140
Microsoft Windows Server 2016 (Server Core installation) 10.0.14393.9140
Microsoft Windows Server 2019 10.0.17763.8755
Microsoft Windows Server 2019 (Server Core installation) 10.0.17763.8755
Microsoft Windows Server 2022 10.0.20348.5139
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2330
Microsoft Windows Server 2025 10.0.26100.32860
Microsoft Windows Server 2025 (Server Core installation) 10.0.26100.32860

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-34330 advisory

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 5 mo ago (2026-05-13)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Microsoft Windows 10 Version 1607
Microsoft Windows 10 Version 1809
Microsoft Windows 10 Version 21H2
Microsoft Windows 10 Version 22H2
Microsoft Windows 11 version 23H2
Microsoft Windows 11 Version 24H2
Microsoft Windows 11 Version 25H2
Microsoft Windows 11 version 26H1
Microsoft Windows Server 2012
Microsoft Windows Server 2012 (Server Core installation)
Microsoft Windows Server 2012 R2
Microsoft Windows Server 2012 R2 (Server Core installation)
Microsoft Windows Server 2016
Microsoft Windows Server 2016 (Server Core installation)
Microsoft Windows Server 2019
Microsoft Windows Server 2019 (Server Core installation)
Microsoft Windows Server 2022
Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)
Microsoft Windows Server 2025
Microsoft Windows Server 2025 (Server Core installation)

Classification

Weakness

CWE-190 Integer Overflow or Wraparound
CWE-416 Use After Free

References

msrc.microsoft.com /update-guide/vulnerability/CVE-2026-34330
vendor-advisory, patch

Sources

CVE List CVE-2026-34330
NVD CVE-2026-34330

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary