CVE-2026-4456: Google Chrome Use After Free Vulnerability

CVE-2026-4456 Overview

CVE-2026-4456 is a use-after-free vulnerability affecting the Digital Credentials API in Google Chrome prior to version 146.0.7680.153. This memory corruption flaw allows a remote attacker who has already compromised the renderer process to potentially perform a sandbox escape via a specially crafted HTML page. The vulnerability is classified as a Use After Free (CWE-416) issue, which occurs when a program continues to use a pointer after the memory it references has been freed.

Critical Impact

Successful exploitation could allow an attacker to escape Chrome's sandbox security boundary, potentially gaining elevated privileges on the underlying system. This represents a significant security risk as sandbox escapes can lead to full system compromise.

Affected Products

• Google Chrome versions prior to 146.0.7680.153
• Google Chrome on Microsoft Windows
• Google Chrome on Apple macOS
• Google Chrome on Linux

Discovery Timeline

• 2026-03-20 - CVE-2026-4456 published to NVD
• 2026-03-20 - Last updated in NVD database

Technical Details for CVE-2026-4456

Vulnerability Analysis

This use-after-free vulnerability resides within the Digital Credentials API implementation in Google Chrome. Use-after-free vulnerabilities occur when a program dereferences a pointer to memory that has been deallocated (freed). In this case, the vulnerability allows an attacker who has already achieved code execution within the renderer process to craft a malicious HTML page that triggers the memory corruption condition.

The Digital Credentials API is designed to handle credential management operations within the browser. When specific sequences of operations are performed through this API, a race condition or improper lifecycle management can cause Chrome to access memory after it has been freed. An attacker can manipulate this freed memory to contain attacker-controlled data, which when accessed by Chrome, can lead to arbitrary code execution outside the renderer sandbox.

The vulnerability requires user interaction (visiting a malicious page) but critically, it enables sandbox escape capabilities, which significantly elevates the impact of any renderer compromise.

Root Cause

The root cause is improper memory management within the Digital Credentials API implementation. The code fails to properly track the lifecycle of memory objects, allowing a scenario where memory is freed while references to it still exist. When these dangling references are subsequently used, the program operates on potentially attacker-controlled data.

This type of flaw typically occurs when:

• Object references are not properly invalidated after the object is destroyed
• Asynchronous operations create timing windows where objects can be freed while still in use
• Complex object ownership models lead to premature deallocation

Attack Vector

The attack vector is network-based, requiring an attacker to first compromise the renderer process through a separate vulnerability or method. Once renderer compromise is achieved, the attacker can leverage this vulnerability by:

1. Creating a malicious HTML page that interacts with the Digital Credentials API
2. Triggering the specific sequence of API calls that cause the use-after-free condition
3. Manipulating the freed memory to contain attacker-controlled data
4. Exploiting the corrupted state to escape the renderer sandbox
5. Achieving code execution with elevated privileges outside the sandbox

The vulnerability requires user interaction to visit the malicious page, but no additional privileges are required for exploitation.

Detection Methods for CVE-2026-4456

Indicators of Compromise

• Unusual memory access patterns or crashes within Chrome processes related to the Digital Credentials API
• Unexpected process spawning from Chrome browser processes
• Chrome renderer processes attempting to access resources outside their sandbox boundaries
• Anomalous network activity originating from Chrome processes after visiting untrusted websites

Detection Strategies

• Monitor for Chrome process crashes with memory corruption signatures, particularly in renderer processes
• Implement endpoint detection rules that alert on Chrome child processes exhibiting sandbox escape behaviors
• Deploy browser-based telemetry to detect unusual Digital Credentials API usage patterns
• Use memory protection technologies that can detect use-after-free exploitation attempts

Monitoring Recommendations

• Enable Chrome's built-in crash reporting and monitor for crashes in the Digital Credentials API component
• Implement network monitoring for connections to known malicious infrastructure following browser activity
• Deploy endpoint detection and response (EDR) solutions capable of monitoring browser process behavior
• Review system logs for evidence of privilege escalation attempts originating from browser processes

How to Mitigate CVE-2026-4456

Immediate Actions Required

• Update Google Chrome to version 146.0.7680.153 or later immediately
• Enable automatic updates in Chrome to receive security patches promptly
• Restrict browsing to trusted websites until patches are applied
• Consider implementing browser isolation technologies for high-risk users

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 146.0.7680.153. The patch corrects the memory management issue in the Digital Credentials API to prevent the use-after-free condition. Organizations should prioritize deploying this update across all managed Chrome installations.

For detailed information about this security update, refer to the Google Chrome Stable Channel Update. Additional technical details may be available in the Chromium Issue Tracker.

Workarounds

• If immediate patching is not possible, consider using an alternative browser until Chrome can be updated
• Implement network-level protections to block access to known malicious sites
• Deploy application whitelisting to prevent unauthorized code execution from browser processes
• Enable Enhanced Safe Browsing in Chrome for additional protection against malicious websites

# Verify Chrome version (should be 146.0.7680.153 or later)
# Navigate to chrome://settings/help or check via command line

# Windows - Check Chrome version via registry
reg query "HKEY_CURRENT_USER\Software\Google\Chrome\BLBeacon" /v version

# Linux - Check Chrome version
google-chrome --version

# macOS - Check Chrome version
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version