CVE-2026-7339: Google Chrome WebRTC Buffer Overflow Flaw

CVE-2026-7339 Overview

A heap buffer overflow vulnerability has been identified in the WebRTC component of Google Chrome prior to version 147.0.7727.138. This memory corruption flaw allows a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability can be triggered when a victim visits a malicious website, enabling attackers to execute arbitrary code or cause application crashes.

Critical Impact

Remote attackers can exploit this heap buffer overflow to achieve code execution or cause denial of service by enticing users to visit malicious web pages containing crafted WebRTC content.

Affected Products

• Google Chrome versions prior to 147.0.7727.138
• Chromium-based browsers using vulnerable WebRTC implementations
• Desktop platforms running affected Chrome versions (Windows, macOS, Linux)

Discovery Timeline

• 2026-04-28 - CVE CVE-2026-7339 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7339

Vulnerability Analysis

This vulnerability is classified as CWE-122 (Heap-based Buffer Overflow), a memory corruption issue where data is written beyond the allocated buffer boundaries on the heap. In this case, the WebRTC component in Google Chrome fails to properly validate buffer sizes when processing certain input, allowing attackers to overflow heap memory regions.

WebRTC (Web Real-Time Communication) is a critical browser component that enables peer-to-peer communication for audio, video, and data sharing directly in web browsers without requiring plugins. The complexity of media processing and codec handling in WebRTC makes it a frequent target for memory corruption vulnerabilities.

The network-based attack vector with low complexity and no privileges required means that any user who visits a malicious webpage can be exploited, though user interaction (visiting the page) is required.

Root Cause

The root cause of this vulnerability lies in improper bounds checking within the WebRTC media processing pipeline. When handling specially crafted data structures in HTML content, the vulnerable code path fails to validate input sizes before writing to heap-allocated buffers, resulting in memory corruption that can be leveraged for exploitation.

Attack Vector

Exploitation of CVE-2026-7339 requires an attacker to craft a malicious HTML page containing specially constructed WebRTC content. When a victim navigates to this page using a vulnerable version of Google Chrome, the crafted content triggers the heap buffer overflow during WebRTC processing.

The attack scenario typically involves:

1. An attacker creates a malicious webpage with crafted WebRTC elements
2. The victim is enticed to visit the malicious page through phishing or malicious advertisements
3. The vulnerable Chrome browser processes the crafted content
4. The heap buffer overflow is triggered, potentially leading to code execution or memory corruption

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

Detection Methods for CVE-2026-7339

Indicators of Compromise

• Unexpected Chrome browser crashes or instability during web browsing
• Anomalous memory usage patterns in Chrome processes, particularly related to WebRTC
• Browser console errors related to WebRTC or media processing failures
• Suspicious network connections initiated after visiting untrusted websites

Detection Strategies

• Monitor browser version inventories to identify systems running Chrome versions prior to 147.0.7727.138
• Implement network monitoring for connections to known malicious domains hosting exploit pages
• Deploy endpoint detection to identify anomalous Chrome process behavior indicative of heap corruption
• Use memory protection tools to detect heap overflow attempts in real-time

Monitoring Recommendations

• Enable Chrome crash reporting to identify potential exploitation attempts
• Monitor web proxy logs for suspicious HTML content patterns associated with WebRTC exploitation
• Implement behavioral analysis to detect post-exploitation activity following browser compromise
• Review system logs for signs of code execution following browser sessions

How to Mitigate CVE-2026-7339

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.138 or later immediately
• Enable automatic Chrome updates to ensure timely patching of future vulnerabilities
• Restrict browsing to trusted websites until patching is complete
• Consider using browser isolation technologies for high-risk browsing activities

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 147.0.7727.138. Organizations should prioritize deploying this update across all systems with Chrome installed. The official release notes and patch details are available in the Google Chrome Update.

For enterprise environments, Chrome updates can be managed through Group Policy or enterprise management tools to ensure consistent deployment across the organization.

Workarounds

• Disable WebRTC in Chrome via flags (chrome://flags/#enable-webrtc) as a temporary measure if immediate patching is not possible
• Use content security policies to restrict WebRTC usage on corporate networks
• Implement network-level filtering to block known malicious domains
• Consider using alternative browsers until Chrome can be updated

# Configuration example
# Chrome enterprise policy to force automatic updates
# Windows Registry configuration for Chrome update policy
reg add "HKLM\SOFTWARE\Policies\Google\Update" /v "AutoUpdateCheckPeriodMinutes" /t REG_DWORD /d 60 /f
reg add "HKLM\SOFTWARE\Policies\Google\Update" /v "UpdateDefault" /t REG_DWORD /d 1 /f