CVE-2026-5886: Google Chrome WebAudio Info Disclosure Flaw

CVE-2026-5886 Overview

An out-of-bounds read vulnerability exists in the WebAudio component of Google Chrome on Mac prior to version 147.0.7727.55. This memory safety issue allows a remote attacker to potentially obtain sensitive information from process memory by enticing a user to visit a specially crafted HTML page. The vulnerability is classified under CWE-125 (Out-of-bounds Read) and has been assigned a medium severity rating by the Chromium security team.

Critical Impact

Remote attackers can exploit this vulnerability to read sensitive information from Chrome's process memory on macOS systems, potentially exposing confidential data, session tokens, or other security-sensitive information stored in memory.

Affected Products

• Google Chrome on Mac prior to version 147.0.7727.55
• Chromium-based browsers on macOS utilizing affected WebAudio components

Discovery Timeline

• April 8, 2026 - CVE-2026-5886 published to NVD
• April 8, 2026 - Last updated in NVD database

Technical Details for CVE-2026-5886

Vulnerability Analysis

This vulnerability stems from improper bounds checking in the WebAudio API implementation within Google Chrome on macOS. The WebAudio API provides powerful capabilities for processing and synthesizing audio in web applications, but the complexity of audio processing operations creates potential attack surfaces when memory access is not properly validated.

When processing audio data through a maliciously crafted HTML page, the vulnerable code fails to adequately verify array boundaries before accessing memory locations. This allows an attacker to read beyond the allocated buffer, potentially exposing sensitive data residing in adjacent memory regions.

The vulnerability specifically affects macOS builds of Chrome, suggesting platform-specific code paths in the WebAudio implementation. Exploitation requires user interaction—specifically visiting a malicious webpage—but no additional authentication or privileges are needed.

Root Cause

The root cause is an out-of-bounds read condition (CWE-125) in the WebAudio component's memory handling routines. When processing specially crafted audio parameters or data structures, the code reads memory beyond the intended buffer boundaries without proper validation. This occurs because bounds checking logic fails to account for certain edge cases in audio processing operations, allowing controlled out-of-bounds memory access.

Attack Vector

An attacker can exploit this vulnerability by crafting a malicious HTML page that leverages the WebAudio API to trigger the out-of-bounds read condition. The attack scenario involves:

1. The attacker creates a webpage containing JavaScript that initializes WebAudio contexts with specifically crafted parameters
2. When a victim visits the page using a vulnerable Chrome version on macOS, the malicious audio processing code executes
3. The crafted parameters cause the WebAudio component to read beyond allocated buffer boundaries
4. Sensitive information from process memory is exposed to the attacker's JavaScript code
5. The leaked data could include memory addresses (defeating ASLR), session data, or other sensitive information

The attack requires no special privileges and can be executed remotely through any delivery mechanism that leads users to visit the malicious page, including phishing emails, malicious advertisements, or compromised websites.

Detection Methods for CVE-2026-5886

Indicators of Compromise

• Unusual WebAudio API usage patterns in browser logs or network traffic
• JavaScript execution attempting to access or exfiltrate memory-related data
• Crash reports indicating memory access violations in Chrome's audio processing components
• Suspicious HTML pages with obfuscated WebAudio initialization code

Detection Strategies

• Monitor for Chrome crash reports related to WebAudio or audio processing components on macOS systems
• Implement web proxy rules to detect and block known malicious payloads targeting WebAudio vulnerabilities
• Deploy endpoint detection rules to identify suspicious memory access patterns in Chrome processes
• Utilize browser telemetry to track anomalous WebAudio API usage that may indicate exploitation attempts

Monitoring Recommendations

• Enable Chrome's built-in crash reporting to capture potential exploitation attempts
• Monitor network traffic for HTML pages containing suspicious WebAudio JavaScript patterns
• Review endpoint logs for Chrome process memory anomalies on macOS endpoints
• Implement alerting for unauthorized information disclosure from browser processes

How to Mitigate CVE-2026-5886

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.55 or later immediately on all macOS systems
• Verify automatic updates are enabled for Chrome across the organization
• Prioritize patching macOS endpoints that access untrusted web content
• Consider implementing browser isolation for high-risk users until patching is complete

Patch Information

Google has released Chrome version 147.0.7727.55 which addresses this vulnerability. Organizations should update all affected Chrome installations on macOS systems immediately. For detailed patch information, refer to the Google Chrome Update Blog and the Chromium Issue Tracker Entry.

Workarounds

• Disable JavaScript execution on untrusted websites using Chrome's site settings until patching is possible
• Utilize browser isolation or virtual browsing environments for accessing untrusted content
• Consider temporarily using alternative browsers on macOS for high-risk browsing activities
• Implement strict content security policies to limit WebAudio API usage from untrusted origins

# Verify Chrome version on macOS
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version

# Force Chrome update check via command line
# Navigate to chrome://settings/help in browser to trigger update

# Enterprise deployment: Update Chrome using managed policy
# Set TargetVersionPrefix to 147.0.7727.55 or higher in management console