# CVE-2026-40403

> Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.

- **CVSS:** 8.8 (HIGH)
- **EPSS:** 0.0%
- **CWE:** CWE-122

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-40403
Full threat coverage + IOCs via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp