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:

1. Attacker hosts a malicious webpage with crafted WebRTC-related content
2. Victim navigates to or is redirected to the malicious page
3. The browser's WebRTC component processes the malicious content
4. Buffer overflow is triggered, corrupting heap memory
5. 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

# 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"