This vulnerability is a heap-based buffer overflow in the Windows Win32K GRFX component that can allow an authorized attacker to elevate local privileges. The weakness arises from unbounded memory operations that can overwrite control data, enabling the attacker to run code with higher privileges. If successful, the attacker could gain full system access, compromising confidentiality, integrity, and availability of the affected system.

Affected users include all versions of Windows 10 that have reached end of mainstream support (Version 1607, 1809, 21H2, 22H2) and Windows 11 releases (23H2, 24H2, 25H2, 26H2, 23H2, 26H1). Server editions from Windows Server 2012 through Windows Server 2025, including Server Core installations, are also impacted. The issue spans both x86 and x64 architectures, as well as ARM64-based Windows 11 variants.

The CVSS score of 7.8 classifies this flaw as high severity, though the EPSS score is not reported. It is not listed in the CISA KEV catalog, indicating no known widespread exploitation. The attack vector requires local access and an authorized user account, so the exploitation risk is limited to environments where privileged users can run arbitrary code within the target system. Because the vulnerability is not remotely exploitable, organizations with strict access controls may have a lower immediate threat, but the high severity still calls for urgent remediation.