CVE-2026-4442: Google Chrome Buffer Overflow Vulnerability

CVE-2026-4442 Overview

A heap buffer overflow vulnerability exists in the CSS parsing engine of Google Chrome prior to version 146.0.7680.153. This memory corruption flaw can be exploited by a remote attacker through a specially crafted HTML page, potentially leading to heap corruption and arbitrary code execution within the context of the browser process.

Critical Impact

Remote attackers can exploit this vulnerability to execute arbitrary code on victim systems by enticing users to visit a malicious webpage containing crafted CSS, potentially leading to complete 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-2026-4442 published to NVD
• 2026-03-20 - Last updated in NVD database

Technical Details for CVE-2026-4442

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), a critical memory corruption issue in Chrome's CSS rendering engine. When the browser parses certain malformed CSS constructs, the CSS parsing component fails to properly validate input boundaries, resulting in heap memory being written beyond its allocated buffer size.

The vulnerability resides in how Chrome's Blink rendering engine processes CSS style declarations. By crafting a malicious HTML page with specifically structured CSS properties, an attacker can trigger an out-of-bounds write condition in the heap memory region. This type of memory corruption can be leveraged to overwrite critical data structures, potentially achieving arbitrary code execution.

The attack requires user interaction—specifically, the victim must navigate to an attacker-controlled webpage or open a malicious HTML document. Once triggered, the heap corruption can be exploited to hijack program control flow, escape the browser sandbox in certain configurations, or cause browser crashes leading to denial of service.

Root Cause

The root cause of CVE-2026-4442 lies in insufficient bounds checking within Chrome's CSS parsing logic. When processing CSS declarations, the parser allocates a heap buffer based on expected input size but fails to properly validate the actual size of incoming data during certain parsing operations. This allows specially crafted CSS values to exceed the allocated buffer boundaries, corrupting adjacent heap memory.

Attack Vector

The attack vector is network-based, requiring a victim to visit a malicious webpage controlled by the attacker. The attack flow typically involves:

1. Attacker creates a webpage containing malicious HTML with crafted CSS
2. Victim is lured to the malicious page via phishing, malvertising, or compromised legitimate sites
3. Chrome's CSS parser processes the malicious stylesheet
4. The heap buffer overflow is triggered during CSS parsing
5. Heap memory corruption occurs, potentially allowing code execution

The vulnerability's exploitation relies on crafted CSS constructs that trigger the improper memory allocation behavior. The attacker must carefully construct the CSS payload to achieve heap corruption in a controlled manner that enables exploitation.

Detection Methods for CVE-2026-4442

Indicators of Compromise

• Unexpected Chrome crashes, particularly when visiting unfamiliar websites
• Memory access violation errors in Chrome process logs
• Suspicious heap corruption patterns detected by endpoint protection solutions
• Unusual network traffic to unknown domains followed by browser instability

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions capable of identifying heap spray and buffer overflow exploitation patterns
• Monitor for anomalous Chrome renderer process behavior including unexpected memory allocation patterns
• Implement network-level inspection for known malicious HTML/CSS patterns
• Enable Chrome's built-in crash reporting to identify potential exploitation attempts

Monitoring Recommendations

• Enable enhanced browser telemetry to capture crash reports and anomalous behavior
• Monitor system event logs for Chrome process crashes with memory corruption signatures
• Implement web proxy logging to track user navigation patterns for incident response
• Deploy memory protection technologies that can detect heap corruption in real-time

How to Mitigate CVE-2026-4442

Immediate Actions Required

• Update Google Chrome to version 146.0.7680.153 or later immediately
• Enable automatic updates in Chrome to ensure timely security patches
• Restrict browsing to trusted websites until patching is complete
• Consider using browser isolation technologies for high-risk users

Patch Information

Google has released Chrome version 146.0.7680.153 to address this vulnerability. Organizations should prioritize updating all Chrome installations across their environment. The security update is available through Chrome's built-in update mechanism and via enterprise deployment channels.

For detailed patch information, see the Google Chrome Stable Channel Update. Additional technical details may be available at the Chromium Issue Tracker.

Workarounds

• Use alternative browsers temporarily while awaiting patch deployment
• Implement web filtering to block access to known malicious domains
• Enable Site Isolation in Chrome enterprise policies for additional process separation
• Deploy browser extensions that block untrusted CSS or JavaScript execution on unknown sites
• Consider network-level inspection to filter potentially malicious HTML content

# Force Chrome update via command line (Windows)
# Navigate to Chrome installation directory and run:
chrome.exe --check-for-update-interval=1

# Verify Chrome version after update
chrome.exe --version
# Expected output: Google Chrome 146.0.7680.153 or higher