Use‑after‑free in the Windows Win32 Kernel Subsystem gives an attacker with local authorization the ability to elevate privileges. The flaw allows the free memory region to be accessed after it has been freed. Based on the description, it is inferred that the exploitation may allow an attacker to execute code with elevated system privileges, potentially compromising confidentiality, integrity and availability of the host.

Microsoft Windows 10 21H2 and 22H2, Windows 11 23H2, 24H2, 25H2, 26H2, 26H1, and Windows Server 2022 and 2025 (including Server Core) are affected. ARM64‑based Windows 11 builds are also impacted.

The CVSS score of 7.8 presents a high‑severity risk for local privilege escalation. With no EPSS score available, the exploitation likelihood is uncertain. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the attack vector is local; an attacker must already have legitimate user access or be able to run code on the target system to trigger the use‑after‑free condition.