CVE-2026-40403 Details
Description
Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.
A heap-based buffer overflow vulnerability has been identified in the Windows Win32K graphics component. This vulnerability allows an authorized attacker to execute code locally. The issue arises from improper handling of memory, which can be exploited to overwrite adjacent memory and potentially execute arbitrary code.
Users can apply the security update for this vulnerability, which is available through the Microsoft Update Catalog. Specific update details can be found in the Microsoft Knowledge Base articles KB5089548, KB5089549, KB5087420, KB5087538, and KB5087471.
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
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40403 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-122 | Heap-based Buffer Overflow | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| microsoft windows 10 1607 | < 10.0.14393.9140 |
CPE
Remediation
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| microsoft windows 10 1809 | < 10.0.17763.8755 |
CPE
Remediation
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| microsoft windows 10 21h2 | < 10.0.19044.7291 |
CPE
Remediation
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| microsoft windows 10 22h2 | < 10.0.19045.7291 |
CPE
Remediation
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| microsoft windows 11 23h2 | < 10.0.22631.7079 |
CPE
Remediation
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| microsoft windows 11 24h2 | < 10.0.26100.8390 |
CPE
Remediation
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| microsoft windows 11 25h2 | < 10.0.26200.8390 |
CPE
Remediation
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| microsoft windows 11 26h1 | < 10.0.28000.2113 |
CPE
Remediation
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| microsoft windows server 2012 | r2 |
CPE
Remediation
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| microsoft windows server 2016 | < 10.0.14393.9140 |
CPE
Remediation
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| microsoft windows server 2019 | < 10.0.17763.8755 |
CPE
Remediation
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| microsoft windows server 2022 | < 10.0.20348.5074 |
CPE
Remediation
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| microsoft windows server 2022 23h2 | < 10.0.25398.2330 |
CPE
Remediation
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| microsoft windows server 2025 | < 10.0.26100.32772 |
CPE
Remediation
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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 15, 2026 | Initial Analysis | [email protected] |
| May 12, 2026 | New CVE Received | [email protected] |