CVE-2026-4676: Google Chrome Use After Free Vulnerability

CVE-2026-4676 Overview

CVE-2026-4676 is a use-after-free vulnerability in the Dawn graphics abstraction layer component of Google Chrome. This memory corruption flaw exists in Chrome versions prior to 146.0.7680.165 and can be exploited by a remote attacker to potentially escape the browser sandbox through a specially crafted HTML page. The vulnerability has been classified with high severity by the Chromium security team.

Critical Impact

Successful exploitation of this use-after-free vulnerability could allow attackers to escape Chrome's sandbox protection, potentially leading to arbitrary code execution outside the browser's security boundary with the privileges of the current user.

Affected Products

• Google Chrome versions prior to 146.0.7680.165
• Affected on Microsoft Windows operating systems
• Affected on Apple macOS operating systems
• Affected on Linux operating systems

Discovery Timeline

• 2026-03-24 - CVE-2026-4676 published to NVD
• 2026-03-24 - Last updated in NVD database

Technical Details for CVE-2026-4676

Vulnerability Analysis

This vulnerability is a classic use-after-free (CWE-416) memory corruption issue residing in Chrome's Dawn component. Dawn serves as the implementation of WebGPU, a modern graphics API that provides high-performance GPU access to web applications. Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it references has been freed, leading to undefined behavior that attackers can exploit.

In this case, the flaw can be triggered remotely when a user visits a malicious webpage containing crafted HTML and JavaScript code designed to manipulate WebGPU resources in a specific sequence. The vulnerability requires user interaction (visiting a malicious page) but no authentication or special privileges, making it accessible to remote attackers.

The most severe implication of this vulnerability is the potential for sandbox escape. Chrome's multi-process architecture uses sandboxing to isolate renderer processes from the operating system. A sandbox escape vulnerability allows malicious code running within the browser to break out of these security boundaries, potentially compromising the entire system.

Root Cause

The root cause of CVE-2026-4676 lies in improper memory management within the Dawn WebGPU implementation. Specifically, the vulnerability occurs when GPU resource objects are freed but references to these objects remain accessible. When these dangling pointers are subsequently dereferenced, the attacker-controlled data that may have been allocated in the freed memory region can be used to hijack program control flow.

Use-after-free vulnerabilities in graphics subsystems are particularly dangerous because:

1. GPU resources involve complex lifecycle management across multiple components
2. The high-performance nature of graphics APIs sometimes leads to optimizations that bypass safety checks
3. Graphics memory can contain executable code or function pointers that enable code execution when corrupted

Attack Vector

The attack vector for CVE-2026-4676 is network-based, requiring a victim to navigate to an attacker-controlled or compromised website. The exploitation sequence involves:

1. The victim visits a malicious webpage containing crafted WebGPU/Dawn API calls
2. The JavaScript code triggers a specific sequence of GPU resource allocations and deallocations
3. The use-after-free condition is triggered, allowing the attacker to corrupt memory
4. The corrupted memory state is leveraged to escape Chrome's sandbox
5. Upon successful sandbox escape, the attacker gains code execution with user-level privileges

No proof-of-concept exploits have been publicly released for this vulnerability. Technical details can be found in the Chromium Issue Tracker Entry.

Detection Methods for CVE-2026-4676

Indicators of Compromise

• Unexpected Chrome renderer process crashes followed by unusual child process spawning behavior
• Anomalous WebGPU API usage patterns in browser telemetry or logging
• Chrome crash reports referencing Dawn or WebGPU components with memory corruption indicators
• Suspicious network connections originating from browser processes to unknown external hosts

Detection Strategies

• Monitor for Chrome browser crashes with crash signatures related to Dawn or GPU process components
• Implement browser version auditing across the enterprise to identify unpatched Chrome installations
• Deploy endpoint detection rules to identify unusual process behavior following browser activity
• Review web proxy logs for connections to known malicious domains serving WebGPU exploit content

Monitoring Recommendations

• Enable Chrome enterprise logging to capture WebGPU-related errors and crashes
• Configure SIEM alerts for patterns consistent with browser exploitation attempts
• Monitor for privilege escalation attempts following Chrome process activity
• Implement memory protection features at the OS level to detect exploitation attempts

How to Mitigate CVE-2026-4676

Immediate Actions Required

• Update Google Chrome to version 146.0.7680.165 or later immediately across all systems
• Enable automatic Chrome updates to ensure timely patching of future vulnerabilities
• Consider using browser isolation solutions for high-risk users until patching is complete
• Review and restrict access to untrusted websites through web filtering solutions

Patch Information

Google has addressed this vulnerability in Chrome version 146.0.7680.165. The fix is included in the stable channel update released on March 23, 2026. Organizations should update Chrome through their standard software deployment mechanisms. For detailed information about the security update, refer to the Google Chrome Update Announcement.

To verify the installed Chrome version:

1. Open Chrome and navigate to chrome://settings/help
2. Confirm the version is 146.0.7680.165 or higher
3. If an update is available, allow it to download and restart the browser

Workarounds

• Disable WebGPU in Chrome via the chrome://flags/#enable-unsafe-webgpu flag as a temporary mitigation
• Use browser group policies to restrict access to websites requiring WebGPU functionality
• Consider using alternative browsers for untrusted web content until Chrome can be updated
• Implement network segmentation to limit the impact of potential sandbox escapes

# Chrome enterprise policy to disable WebGPU (Windows Registry example)
reg add "HKLM\SOFTWARE\Policies\Google\Chrome" /v WebGPUEnabled /t REG_DWORD /d 0 /f

# Verify Chrome version via command line
google-chrome --version
# Expected output: Google Chrome 146.0.7680.165 or higher