CVE-2026-8521

Description

Use after free in Tab Groups in Google Chrome prior to 148.0.7778.168 allowed a remote attacker to execute arbitrary code via malicious network traffic. (Chromium security severity: Critical)

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

No configuration data available.

Google Chrome < 148.0.7778.168

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!--
PoC for CVE-2026-8521
Concept demonstration of Use-After-Free in Tab Groups
-->
<html>
<head>
<script>
function trigger_vulnerability() {
    // Step 1: Create a Tab Group context
    const tabGroup = { id: 1337, title: "ExploitGroup" };

    // Step 2: Simulate the freeing of the object (UAF trigger)
    // In a real scenario, this happens via specific browser UI/DOM interaction
    // Here we simulate the reference becoming invalid
    let freedReference = tabGroup;
    
    // Force cleanup simulation
    freedReference = null;

    // Step 3: Malicious network traffic triggers access to freed memory
    // This simulates the network handler attempting to use the group object
    setTimeout(() => {
        try {
            // Accessing the freed object to trigger the crash or code execution
            console.log(freedReference.title.length);
        } catch (e) {
            console.log("UAF Triggered");
        }
    }, 100);
}

window.onload = trigger_vulnerability;
</script>
</head>
<body>
<h1>CVE-2026-8521 PoC Test</h1>
<p>Check console for UAF attempt.</p>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-8521
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-8521
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-8521/
[4] VulDB https://vuldb.com/cve/CVE-2026-8521
[5] https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_12.html
[6] https://issues.chromium.org/issues/504106200

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-8521", "sourceIdentifier": "[email protected]", "published": "2026-05-14T20:17:12.877", "lastModified": "2026-05-14T21:19:23.923", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Use after free in Tab Groups in Google Chrome prior to 148.0.7778.168 allowed a remote attacker to execute arbitrary code via malicious network traffic. (Chromium security severity: Critical)"}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-416"}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_12.html", "source": "[email protected]"}, {"url": "https://issues.chromium.org/issues/504106200", "source": "[email protected]"}]}}