CVE-2026-7940

// Conceptual PoC for CVE-2026-7940 // This demonstrates the structure of a malicious extension that would trigger the UAF. // File: manifest.json /* { "manifest_version": 3, "name": "Exploit Demo", "version": "1.0", "background": { "service_worker": "exploit.js" } } */ // File: exploit.js // Triggering the Use-After-Free in V8 function triggerExploit() { // 1. Spray heap to groom memory let buffer = new ArrayBuffer(1024); let view = new Uint8Array(buffer); // 2. Create the object that will be freed prematurely let vulnerableObject = { data: "sensitive" }; // 3. Perform operations that trigger the UAF bug in V8 < 148.0.7778.96 // (Specific V8 internal logic goes here) // 4. Attempt to access the freed memory try { console.log(vulnerableObject.data); } catch (e) { // Failure or crash indicates potential corruption } } triggerExploit();

{"cve": {"id": "CVE-2026-7940", "sourceIdentifier": "[email protected]", "published": "2026-05-06T19:16:42.323", "lastModified": "2026-05-06T23:33:48.200", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in V8 in Google Chrome prior to 148.0.7778.96 allowed an attacker who convinced a user to install a malicious extension to execute arbitrary code inside a sandbox 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:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "148.0.7778.96", "matchCriteriaId": "5E9416A8-4333-4195-983C-78F521AF6245"}]}, {"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/2026/05/stable-channel-update-for-desktop.html", "source": "[email protected]", "tags": ["Vendor Advisory"]}, {"url": "https://issues.chromium.org/issues/493631402", "source": "[email protected]", "tags": ["Issue Tracking", "Permissions Required"]}]}}