CVE-2025-9478: Google Chrome Use After Free Vulnerability

CVE-2025-9478 Overview

CVE-2025-9478 is a critical use-after-free vulnerability in the ANGLE (Almost Native Graphics Layer Engine) component of Google Chrome prior to version 139.0.7258.154. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption via a crafted HTML page, enabling arbitrary code execution within the context of the browser process.

ANGLE is Chrome's graphics abstraction layer that translates OpenGL ES API calls to platform-specific graphics APIs (Direct3D, OpenGL, Metal, or Vulkan). Due to its critical role in rendering WebGL content and handling complex graphics operations, vulnerabilities in this component can have severe security implications.

Critical Impact

Remote attackers can achieve arbitrary code execution by exploiting heap corruption through maliciously crafted web content, potentially leading to complete system compromise.

Affected Products

• Google Chrome versions prior to 139.0.7258.154 on Windows
• Google Chrome versions prior to 139.0.7258.154 on macOS
• Google Chrome versions prior to 139.0.7258.154 on Linux

Discovery Timeline

• 2025-08-26 - CVE-2025-9478 published to NVD
• 2025-09-02 - Last updated in NVD database

Technical Details for CVE-2025-9478

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption vulnerability class where a program continues to use a pointer after the memory it references has been freed. In the context of ANGLE, this occurs during graphics object lifecycle management, where improper handling of memory deallocation leads to dangling pointer references.

The vulnerability can be triggered remotely through specially crafted HTML pages containing malicious WebGL or graphics content. When a user visits a compromised website, the attacker-controlled content can manipulate the ANGLE rendering pipeline to trigger the use-after-free condition, potentially corrupting heap memory structures.

Successful exploitation requires user interaction (visiting a malicious page) but requires no privileges or authentication. The attack can be executed entirely over the network, making drive-by attacks a significant concern. Exploitation could result in arbitrary code execution with the privileges of the Chrome process, leading to potential system compromise, data theft, or installation of malware.

Root Cause

The root cause lies in improper memory management within the ANGLE graphics abstraction layer. Specifically, a graphics object is freed prematurely while references to that object still exist elsewhere in the rendering pipeline. When subsequent operations attempt to access this freed memory, the use-after-free condition occurs.

This type of vulnerability typically arises from complex object lifecycle management in graphics rendering code, where multiple components may hold references to shared resources. Race conditions in asynchronous rendering operations or improper reference counting can lead to premature deallocation scenarios.

Attack Vector

The attack vector is network-based, requiring the victim to navigate to a malicious webpage containing specially crafted HTML and JavaScript code. The attacker constructs web content that manipulates WebGL or other graphics APIs to trigger specific sequences of ANGLE operations that exploit the memory management flaw.

The exploitation typically follows this pattern: the attacker crafts content that causes allocation of a graphics object, triggers premature freeing of that object through specific API call sequences, and then forces reuse of the freed memory with attacker-controlled data. This heap corruption can then be leveraged to achieve arbitrary code execution through techniques such as vtable hijacking or function pointer overwriting.

For detailed technical information about this vulnerability, refer to the Chromium Issue Tracker Entry.

Detection Methods for CVE-2025-9478

Indicators of Compromise

• Unexpected Chrome browser crashes or instability, particularly when visiting unknown websites
• Memory access violations or heap corruption errors in Chrome process logs
• Anomalous network connections originating from Chrome after visiting suspicious pages
• Suspicious child processes spawned by Chrome browser processes

Detection Strategies

• Monitor for Chrome versions older than 139.0.7258.154 across the enterprise using asset management tools
• Implement web filtering to block known malicious domains attempting to exploit browser vulnerabilities
• Deploy endpoint detection solutions capable of identifying heap spray and memory corruption exploitation attempts
• Enable Chrome's built-in crash reporting and monitor for ANGLE-related crash signatures

Monitoring Recommendations

• Configure SIEM to alert on Chrome crash dumps containing ANGLE or graphics-related stack traces
• Monitor browser telemetry for anomalous WebGL usage patterns that may indicate exploitation attempts
• Implement network-level monitoring for unusual outbound connections following browser rendering activity
• Review endpoint security logs for suspicious process behavior originating from Chrome processes

How to Mitigate CVE-2025-9478

Immediate Actions Required

• Update Google Chrome to version 139.0.7258.154 or later immediately across all systems
• Enable automatic Chrome updates to ensure timely deployment of security patches
• Consider temporarily disabling WebGL in Chrome for high-risk environments until patches are deployed
• Implement browser isolation technologies to contain potential exploitation attempts

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 139.0.7258.154. Organizations should prioritize deployment of this update across all managed endpoints. The patch addresses the memory management issue in ANGLE that allows the use-after-free condition to occur.

For complete details on this security update, refer to the Google Chrome Stable Channel Update.

Workarounds

• Disable WebGL in Chrome by navigating to chrome://flags/#disable-webgl and enabling the flag
• Use enterprise policies to restrict access to untrusted websites pending patch deployment
• Implement network-level content filtering to block potentially malicious graphics content
• Consider deploying browser isolation solutions to contain browser-based exploitation attempts

# Chrome enterprise policy to disable WebGL (Windows Registry)
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# Create DWORD: WebGLDisabled = 1

# Linux/macOS managed preferences
# Add to Chrome policy JSON:
# { "WebGLDisabled": true }