CVE-2026-7350: Google Chrome WebMIDI Use After Free Flaw

CVE-2026-7350 Overview

A use after free vulnerability exists in the WebMIDI component of Google Chrome prior to version 147.0.7727.138. This memory corruption flaw allows a remote attacker who has already compromised the renderer process to potentially escape the browser sandbox through a specially crafted HTML page. The vulnerability poses significant risk as successful exploitation could allow attackers to break out of Chrome's sandbox isolation and execute code with elevated privileges on the underlying system.

Critical Impact
Remote attackers with renderer process access can potentially escape Chrome's sandbox through a use after free condition in WebMIDI, enabling arbitrary code execution outside browser isolation.

Affected Products

Google Chrome prior to version 147.0.7727.138
Chromium-based browsers prior to version 147.0.7727.138
Any software embedding Chromium WebMIDI component prior to the patched version

Discovery Timeline

2026-04-28 - CVE-2026-7350 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7350

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption issue where the application continues to reference memory after it has been freed. In the context of the WebMIDI implementation in Google Chrome, an attacker who has already achieved initial code execution within the renderer sandbox can leverage this flaw to potentially escape the sandbox boundary.

The vulnerability requires user interaction (visiting a malicious page) and exploiting it involves high complexity as the attacker must first compromise the renderer process before attempting the sandbox escape. Despite these prerequisites, successful exploitation carries severe consequences as it enables code execution outside of Chrome's security sandbox, potentially compromising the entire system.

Root Cause

The root cause lies in improper memory lifecycle management within Chrome's WebMIDI API implementation. WebMIDI provides JavaScript APIs for interacting with MIDI devices, and during the handling of MIDI-related objects, the code fails to properly track object lifetimes. This results in a dangling pointer scenario where freed memory can be subsequently accessed, allowing attackers to manipulate program execution flow by controlling the contents of the freed memory region.

Attack Vector

The attack requires a multi-stage exploitation approach. First, the attacker must compromise the renderer process, typically through a separate vulnerability or by crafting specific JavaScript that triggers memory corruption. Once renderer access is achieved, the attacker can craft specific WebMIDI API calls that trigger the use after free condition. By carefully controlling heap memory allocations, an attacker can reclaim the freed memory with attacker-controlled data, ultimately achieving code execution outside the sandbox.

The vulnerability is network-accessible, meaning a victim only needs to visit a malicious webpage to be at risk. However, the changed scope indicator in the vulnerability assessment reflects that successful exploitation affects resources beyond the vulnerable component—specifically, it can break out of the Chrome sandbox to affect the host operating system.

Detection Methods for CVE-2026-7350

Indicators of Compromise

Unexpected crashes or memory access violations in Chrome's WebMIDI component
Unusual process behavior following browser crashes, particularly child processes spawning with elevated privileges
Memory dump analysis showing freed heap objects being accessed in WebMIDI-related code paths

Detection Strategies

Monitor for Chrome versions below 147.0.7727.138 across the enterprise environment
Implement endpoint detection rules for unusual process chains originating from Chrome renderer processes
Deploy memory corruption detection tools that can identify use after free patterns in browser processes
Review security logs for browser crash reports mentioning WebMIDI components

Monitoring Recommendations

Enable Chrome's crash reporting and centralize crash logs for analysis of WebMIDI-related failures
Configure endpoint protection to alert on sandbox escape attempts from browser processes
Monitor network traffic for access to known malicious pages targeting browser vulnerabilities
Implement browser version compliance monitoring to ensure timely patch deployment

How to Mitigate CVE-2026-7350

Immediate Actions Required

Update Google Chrome to version 147.0.7727.138 or later immediately
Update all Chromium-based browsers (Edge, Brave, Opera, etc.) to their equivalent patched versions
Consider temporarily disabling WebMIDI functionality if updates cannot be applied immediately using Chrome enterprise policies

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 147.0.7727.138. The fix corrects the memory management issue in the WebMIDI implementation to prevent use after free conditions. Organizations should reference the Google Chrome Stable Update for complete details on this security release.

Additional technical details can be found in the Chromium Issue Tracker Entry.

Workarounds

Disable WebMIDI API access through Chrome enterprise policies by setting the DefaultWebMidiSetting policy to 2 (Block)
Implement browser isolation solutions to contain potential sandbox escapes
Use network-level filtering to block access to known malicious domains targeting browser vulnerabilities
Consider restricting users to known-safe websites until patching is complete

bash

# Chrome Enterprise Policy to disable WebMIDI
# Add to Chrome policy configuration file
{
  "DefaultWebMidiSetting": 2
}
# Value 2 = Block sites from using WebMIDI API