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CVE-2026-40403 - Vulnerability Analysis

HighCVSS: 8.8

Last Updated: May 12, 2026

Windows Win32K - Buffer Overflow

Published: May 12, 2026Updated: May 12, 2026

Overview

Windows Win32K contains a heap-based buffer overflow in GRFX, letting authorized attackers execute code locally, exploit requires local access with authorization.

Severity & Score

Severity: High

CVSS Score: 8.8

Impact

Authorized local attackers can execute arbitrary code, potentially leading to full system compromise.

Mitigation

Update to the latest Windows version with security patches.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40403

Related Resources

Vulnerability Intelligence Dashboard
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Details

CVE ID: CVE-2026-40403
Severity: High
CVSS Score: 8.8
Type: buffer_overflow
Status: new

CWE

CWE-122

CVSS Metrics

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H