CVE-2026-4463: Google Chrome Buffer Overflow Vulnerability

CVE-2026-4463 Overview

A heap buffer overflow vulnerability has been identified in the WebRTC component of Google Chrome prior to version 146.0.7680.153. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. When a user visits a malicious webpage, the attacker can trigger the overflow condition, potentially leading to arbitrary code execution within the context of the browser process.

Critical Impact
Remote attackers can exploit this heap corruption vulnerability to achieve code execution, compromise user data confidentiality, and take control of affected systems through malicious web content.

Affected Products

Google Chrome versions prior to 146.0.7680.153
Affected on Microsoft Windows operating systems
Affected on Apple macOS operating systems
Affected on Linux operating systems

Discovery Timeline

2026-03-20 - CVE-2026-4463 published to NVD
2026-03-20 - Last updated in NVD database

Technical Details for CVE-2026-4463

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), a critical memory corruption issue affecting the WebRTC implementation in Google Chrome. WebRTC (Web Real-Time Communication) is a complex component that handles real-time audio, video, and data sharing capabilities directly within web browsers.

The heap buffer overflow occurs when WebRTC improperly handles certain operations, allowing data to be written beyond the allocated buffer boundaries on the heap. This type of vulnerability is particularly dangerous in browser contexts because WebRTC is exposed to potentially untrusted web content. An attacker can craft malicious HTML or JavaScript that triggers the vulnerable code path, causing the overflow condition.

Successful exploitation could allow an attacker to corrupt heap metadata, overwrite adjacent memory structures, and potentially achieve arbitrary code execution. Given WebRTC's network-accessible nature and the requirement for user interaction (visiting a malicious page), this represents a significant attack surface for drive-by download scenarios.

Root Cause

The root cause is a heap-based buffer overflow (CWE-122) in the WebRTC component where boundary checking is insufficient during memory operations. When processing certain malformed or specially crafted data through WebRTC functions, the code fails to properly validate buffer sizes before write operations, allowing an attacker to overflow heap-allocated buffers.

Attack Vector

The attack is conducted remotely over the network and requires user interaction. An attacker must entice a victim to visit a malicious webpage containing crafted HTML or JavaScript that triggers the vulnerable WebRTC code path. The attack does not require authentication or special privileges beyond convincing the user to navigate to the attacker-controlled page.

The exploitation flow typically involves:

Attacker hosts a malicious webpage with crafted WebRTC-related content
Victim navigates to or is redirected to the malicious page
The browser's WebRTC component processes the malicious content
Buffer overflow is triggered, corrupting heap memory
Attacker gains code execution within the Chrome renderer process

Due to Chrome's sandbox architecture, additional sandbox escape techniques may be required for full system compromise. However, even within the sandbox, attackers can potentially access sensitive browser data and perform actions in the user's context.

Detection Methods for CVE-2026-4463

Indicators of Compromise

Unusual Chrome process crashes or abnormal termination events related to WebRTC components
Unexpected network connections initiated by Chrome renderer processes
Memory access violations or heap corruption errors in browser crash logs
Suspicious JavaScript or HTML content attempting to abuse WebRTC APIs

Detection Strategies

Monitor Chrome crash reports for WebRTC-related stack traces indicating heap corruption
Deploy endpoint detection solutions to identify anomalous browser behavior and memory manipulation attempts
Implement web content filtering to block known malicious domains serving exploit code
Analyze network traffic for unusual WebRTC signaling patterns or malformed data streams

Monitoring Recommendations

Enable Chrome enterprise logging to capture browser events and crash data centrally
Configure endpoint protection platforms to alert on suspicious Chrome child process behavior
Monitor for rapid or repeated WebRTC initialization attempts that may indicate exploitation attempts
Implement browser isolation technologies for high-risk browsing scenarios

How to Mitigate CVE-2026-4463

Immediate Actions Required

Update Google Chrome to version 146.0.7680.153 or later immediately across all managed endpoints
Enable automatic Chrome updates to ensure timely patching of future vulnerabilities
Consider disabling WebRTC temporarily in high-security environments if updates cannot be immediately applied
Educate users about the risks of visiting untrusted websites

Patch Information

Google has released Chrome version 146.0.7680.153 which addresses this vulnerability. Organizations should prioritize this update given the high severity rating and potential for remote code execution. The patch is available through standard Chrome update channels.

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

Workarounds

Disable WebRTC functionality via Chrome flags (chrome://flags/#enable-webrtc) if real-time communication features are not required
Use browser extensions that block WebRTC to reduce attack surface
Implement network-level content filtering to block known malicious sites
Deploy browser isolation solutions to contain potential exploitation attempts
Restrict browser access to trusted sites only through enterprise policies

bash

# Chrome Enterprise Policy to force minimum version
# Add to Chrome Enterprise policies (Windows Registry or macOS plist)
# Minimum required version to address CVE-2026-4463
# Policy: MinimumChromeVersionRequired = 146.0.7680.153

# For Linux/macOS, disable WebRTC via command line flag (temporary workaround)
google-chrome --disable-webrtc

# Windows Registry path for Enterprise policies
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# Create DWORD: MinimumChromeVersionRequired = "146.0.7680.153"