CVE-2026-6297: Google Chrome Proxy Use-After-Free Flaw

CVE-2026-6297 Overview

CVE-2026-6297 is a critical use-after-free vulnerability in the Proxy component of Google Chrome prior to version 147.0.7727.101. This memory corruption flaw allows an attacker positioned in a privileged network location to potentially perform a sandbox escape via a crafted HTML page. The vulnerability is classified as CWE-416 (Use After Free) and represents a severe security risk due to its potential to bypass Chrome's sandbox protections.

Critical Impact

Successful exploitation of this use-after-free vulnerability could allow attackers to escape Chrome's security sandbox, potentially leading to full system compromise through arbitrary code execution outside the browser's isolated environment.

Affected Products

• Google Chrome versions prior to 147.0.7727.101
• Chromium-based browsers using affected Proxy component
• All platforms running vulnerable Chrome versions (Windows, macOS, Linux)

Discovery Timeline

• April 15, 2026 - CVE-2026-6297 published to NVD
• April 15, 2026 - Last updated in NVD database

Technical Details for CVE-2026-6297

Vulnerability Analysis

This use-after-free vulnerability exists within Chrome's Proxy handling component. Use-after-free conditions occur when a program continues to reference memory after it has been freed, allowing attackers to manipulate the contents of the freed memory region. In this case, the vulnerability enables a sandbox escape, which is particularly severe as Chrome's sandbox is a critical security boundary designed to contain malicious code.

The attack requires the adversary to be in a privileged network position, suggesting the vulnerability may be triggered through network proxy interactions or man-in-the-middle scenarios. The scope change indicated in the vulnerability assessment means that a successful exploit can impact resources beyond the vulnerable component's security scope, crossing the sandbox boundary.

Root Cause

The root cause stems from improper memory management in Chrome's Proxy subsystem. When certain proxy-related operations are performed, memory is freed but references to that memory are retained. An attacker can trigger specific conditions that cause the freed memory to be reallocated with attacker-controlled data, which is then accessed through the dangling pointer, leading to arbitrary code execution.

Attack Vector

The attack requires user interaction—specifically, the victim must visit a maliciously crafted HTML page while the attacker is in a privileged network position. This network position could be achieved through compromised network infrastructure, rogue access points, or man-in-the-middle techniques. Once the victim loads the malicious page, the crafted content triggers the use-after-free condition in the Proxy component, enabling the sandbox escape.

The vulnerability is exploitable remotely over the network, though the high attack complexity reflects the requirement for the attacker to maintain a privileged network position. No authentication is required, but user interaction is necessary to visit the malicious page.

Detection Methods for CVE-2026-6297

Indicators of Compromise

• Unusual Chrome process behavior including unexpected child process spawning outside the sandbox
• Anomalous network proxy configuration changes or suspicious proxy-related network traffic
• Memory corruption artifacts in Chrome crash dumps referencing the Proxy component
• Unexpected system-level access originating from Chrome renderer processes

Detection Strategies

• Monitor for Chrome processes attempting to access resources outside normal sandbox boundaries
• Implement network monitoring to detect suspicious proxy manipulation or MITM activity
• Deploy endpoint detection rules for use-after-free exploitation patterns in browser processes
• Enable Chrome crash reporting and analyze dumps for Proxy component memory corruption signatures

Monitoring Recommendations

• Configure SIEM alerts for Chrome processes spawning unexpected child processes with elevated privileges
• Monitor network traffic for anomalous proxy negotiation patterns that could indicate exploitation attempts
• Enable detailed Chrome logging and forward to security monitoring infrastructure
• Deploy behavioral analysis to detect post-exploitation activity following sandbox escape

How to Mitigate CVE-2026-6297

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.101 or later immediately
• Enable automatic Chrome updates to ensure timely security patch deployment
• Audit network infrastructure for potential privileged attacker positions
• Implement network segmentation to reduce MITM attack surface
• Consider temporarily restricting access to untrusted networks until patching is complete

Patch Information

Google has released Chrome version 147.0.7727.101 which addresses this vulnerability. The patch resolves the use-after-free condition in the Proxy component by implementing proper memory management and ensuring references are invalidated when memory is freed.

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

Workarounds

• Restrict browsing to trusted networks and avoid public or untrusted Wi-Fi until patching is complete
• Implement strict proxy policies through enterprise management to prevent manipulation
• Use VPN connections to reduce exposure to privileged network position attacks
• Consider deploying network-level protections against MITM attacks such as DNSSEC and certificate pinning

# Verify Chrome version (should be 147.0.7727.101 or higher)
google-chrome --version

# Force Chrome update check on Linux
google-chrome --check-for-update-interval=1

# Enterprise deployment: Update Chrome via policy
# Windows Group Policy or Chrome Browser Cloud Management
# Ensure "Update policy override" is set to "Always allow updates"