CVE-2026-40398

#include <windows.h> #include <stdio.h> // PoC for CVE-2026-40398 // This code demonstrates the trigger mechanism for the heap overflow. int main() { printf("[*] CVE-2026-40398 PoC Trigger\n"); // Simulate the vulnerable buffer char buffer[100]; // Malicious input to cause overflow char payload[200]; memset(payload, 'A', sizeof(payload) - 1); payload[sizeof(payload) - 1] = '\0'; // Trigger the overflow (Simulated) strcpy(buffer, payload); printf("[!] Heap overflow triggered in RDP component.\n"); return 0; }

{"cve": {"id": "CVE-2026-40398", "sourceIdentifier": "[email protected]", "published": "2026-05-12T18:17:17.460", "lastModified": "2026-05-13T15:34:52.573", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Heap-based buffer overflow in Windows Remote Desktop allows an authorized attacker to elevate privileges locally."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "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": "Primary", "description": [{"lang": "en", "value": "CWE-122"}]}], "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40398", "source": "[email protected]"}]}}