Win32k Elevation of Privilege Vulnerability
CVE-2026-34331 is fixed in 31 products on 1 platform, first by KB5087537, released May 12, 2026. It is not reported as exploited. Patch Radar priority: High.
<p>Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Win32K - GRFX allows an authorized attacker to elevate privileges locally.</p>
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Microsoft | |||
| Windows 10 Version 1607 for 32-bit Systems | 14393.9140 | KB5087537 | May 12, 2026 |
| Windows 10 Version 1607 for x64-based Systems | 14393.9140 | KB5087537 | May 12, 2026 |
| Windows 10 Version 1809 for 32-bit Systems | 17763.8755 | KB5087538 | May 12, 2026 |
| Windows 10 Version 1809 for x64-based Systems | 17763.8755 | KB5087538 | May 12, 2026 |
| Windows 10 Version 21H2 for 32-bit Systems | KB5087544 | May 12, 2026 | |
| Windows 10 Version 21H2 for ARM64-based Systems | KB5087544 | May 12, 2026 | |
| Windows 10 Version 21H2 for x64-based Systems | KB5087544 | May 12, 2026 | |
| Windows 10 Version 22H2 for 32-bit Systems | KB5094127 | Jun 9, 2026 | |
| Windows 10 Version 22H2 for ARM64-based Systems | KB5094127 | Jun 9, 2026 | |
| Windows 10 Version 22H2 for x64-based Systems | KB5094127 | Jun 9, 2026 | |
| Windows 11 Version 23H2 for ARM64-based Systems | 22631.7079 | KB5087420 | May 12, 2026 |
| Windows 11 Version 23H2 for x64-based Systems | 22631.7219 | KB5093998 | Jun 9, 2026 |
| Windows 11 Version 24H2 for ARM64-based Systems | KB5089549 | May 12, 2026 | |
| Windows 11 Version 24H2 for ARM64-based Systems | KB5089466 | May 12, 2026 | |
| Windows 11 Version 24H2 for x64-based Systems | KB5089549 | May 12, 2026 | |
| Windows 11 Version 24H2 for x64-based Systems | KB5089466 | May 12, 2026 | |
| Windows 11 Version 25H2 for ARM64-based Systems | KB5089549 | May 12, 2026 | |
| Windows 11 Version 25H2 for ARM64-based Systems | KB5089466 | May 12, 2026 | |
| Windows 11 Version 25H2 for x64-based Systems | KB5089549 | May 12, 2026 | |
| Windows 11 Version 25H2 for x64-based Systems | KB5089466 | May 12, 2026 | |
| Windows 11 Version 26H1 for ARM64-based Systems | 28000.2113 | KB5089548 | May 12, 2026 |
| Windows 11 version 26H1 for x64-based Systems | 28000.2113 | KB5089548 | May 12, 2026 |
| Windows Server 2012 | KB5087470 | May 12, 2026 | |
| Windows Server 2012 (Server Core installation) | KB5087470 | May 12, 2026 | |
| Windows Server 2012 R2 | KB5087471 | May 12, 2026 | |
| Windows Server 2012 R2 (Server Core installation) | KB5087471 | May 12, 2026 | |
| Windows Server 2016 | 14393.9140 | KB5087537 | May 12, 2026 |
| Windows Server 2016 (Server Core installation) | 14393.9140 | KB5087537 | May 12, 2026 |
| Windows Server 2019 | 17763.8755 | KB5087538 | May 12, 2026 |
| Windows Server 2019 (Server Core installation) | 17763.8755 | KB5087538 | May 12, 2026 |
| Windows Server 2022 | 20348.5074 | KB5087424 | May 12, 2026 |
| Windows Server 2022 | 20348.5139 | KB5087545 | May 12, 2026 |
| Windows Server 2022 (Server Core installation) | 20348.5074 | KB5087424 | May 12, 2026 |
| Windows Server 2022 (Server Core installation) | 20348.5139 | KB5087545 | May 12, 2026 |
| Windows Server 2022, 23H2 Edition (Server Core installation) | 25398.2330 | KB5087541 | May 12, 2026 |
| Windows Server 2025 | 26100.32860 | KB5087539 | May 12, 2026 |
| Windows Server 2025 | 26100.32772 | KB5087423 | May 12, 2026 |
| Windows Server 2025 (Server Core installation) | 26100.32860 | KB5087539 | May 12, 2026 |
| Windows Server 2025 (Server Core installation) | 26100.32772 | KB5087423 | May 12, 2026 |
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