CVE-2025-5959: Google Chrome V8 RCE Vulnerability

CVE-2025-5959 Overview

CVE-2025-5959 is a Type Confusion vulnerability in the V8 JavaScript engine used by Google Chrome. This vulnerability exists in versions prior to 137.0.7151.103 and allows a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. The vulnerability has been classified with Chromium security severity as High.

Critical Impact

Remote attackers can achieve arbitrary code execution within the browser sandbox by exploiting the type confusion in V8, potentially leading to information disclosure, data manipulation, or further system compromise if combined with sandbox escape techniques.

Affected Products

• Google Chrome versions prior to 137.0.7151.103
• All platforms running vulnerable Chrome versions (Windows, macOS, Linux)
• Chromium-based browsers that incorporate the vulnerable V8 engine version

Discovery Timeline

• 2025-06-11 - CVE-2025-5959 published to NVD
• 2025-06-16 - Last updated in NVD database

Technical Details for CVE-2025-5959

Vulnerability Analysis

This vulnerability (CWE-843: Access of Resource Using Incompatible Type - Type Confusion) occurs in Google Chrome's V8 JavaScript engine. Type confusion vulnerabilities arise when code treats a memory resource as if it were a different type than it actually is, leading to unpredictable behavior including memory corruption.

In the context of V8, the JavaScript engine performs various optimizations that rely on accurate type information. When the engine incorrectly assumes the type of an object during execution, it may process memory in an unintended manner, potentially allowing an attacker to manipulate memory contents or control execution flow.

The vulnerability requires user interaction—specifically, a victim must navigate to a malicious HTML page crafted by the attacker. Once triggered, the vulnerability can lead to arbitrary code execution within Chrome's sandbox environment.

Root Cause

The root cause is a type confusion flaw in the V8 JavaScript engine. V8 performs aggressive optimizations based on type assumptions during JavaScript code compilation and execution. When these assumptions are violated through carefully crafted JavaScript code, the engine may misinterpret memory contents, treating one type of object as another. This can lead to out-of-bounds memory access, corruption of internal V8 structures, or manipulation of object properties in unintended ways.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker must host or inject a malicious HTML page containing specially crafted JavaScript code designed to trigger the type confusion in V8. When a victim visits the malicious page using a vulnerable version of Chrome, the JavaScript engine processes the attacker's code, triggering the type confusion and enabling arbitrary code execution within the browser's sandbox.

The attack scenario typically involves:

1. Attacker creates a malicious webpage with crafted JavaScript
2. Victim is lured to visit the page (via phishing, malvertising, or compromised websites)
3. V8 engine processes the JavaScript, triggering type confusion
4. Attacker achieves code execution within the Chrome sandbox

While the code execution is sandboxed, this vulnerability could be chained with sandbox escape vulnerabilities for full system compromise.

Detection Methods for CVE-2025-5959

Indicators of Compromise

• Unusual Chrome process crashes or stability issues when visiting certain websites
• Unexpected memory consumption patterns in Chrome renderer processes
• Browser crashes accompanied by V8-related error messages in crash dumps
• Network connections to suspicious domains serving JavaScript-heavy content

Detection Strategies

• Monitor Chrome browser version deployments across the organization to identify unpatched instances
• Implement endpoint detection rules for anomalous Chrome renderer process behavior
• Deploy web proxy or gateway solutions to inspect and block known malicious JavaScript patterns
• Use browser isolation technologies to contain potential exploitation attempts

Monitoring Recommendations

• Enable Chrome crash reporting and analyze crash dumps for V8-related type confusion indicators
• Monitor network traffic for connections to newly registered or suspicious domains serving JavaScript
• Implement application control policies to ensure only approved Chrome versions are deployed
• Review browser extension activity that may redirect users to malicious pages

How to Mitigate CVE-2025-5959

Immediate Actions Required

• Update Google Chrome to version 137.0.7151.103 or later immediately
• Enable automatic Chrome updates across all managed endpoints
• Verify update deployment through enterprise management tools or browser version auditing
• Consider using browser isolation for high-risk users until patching is complete

Patch Information

Google has released a security update addressing this vulnerability. The fix is included in Chrome version 137.0.7151.103 and later. Organizations should update Chrome through their standard update mechanisms. For enterprise deployments, administrators can push updates via Google's enterprise update policies or third-party patch management solutions.

For detailed information about the update, refer to the Google Chrome Stable Channel Update announcement. Technical details about the vulnerability can be found in the Chromium Issue Tracker.

Workarounds

• Enable Site Isolation in Chrome to provide additional process separation
• Consider disabling JavaScript on untrusted websites as a temporary measure (may impact functionality)
• Use browser isolation solutions to execute web content in isolated environments
• Implement strict web filtering to block access to unknown or suspicious websites

# Verify Chrome version via command line
# Windows
"C:\Program Files\Google\Chrome\Application\chrome.exe" --version

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

# Linux
google-chrome --version

# Expected output should show version 137.0.7151.103 or higher