CVE-2026-6318: Google Chrome Codecs Use-After-Free Flaw

CVE-2026-6318 Overview

A use-after-free vulnerability has been identified in the Codecs component of Google Chrome prior to version 147.0.7727.101. This memory corruption flaw allows a remote attacker to execute arbitrary code within the browser's sandbox by convincing a user to visit a specially crafted HTML page. The vulnerability stems from improper memory management in media codec processing, where freed memory regions may be accessed after deallocation.

Critical Impact

Remote attackers can achieve arbitrary code execution within the Chrome sandbox by exploiting this use-after-free vulnerability through malicious web content.

Affected Products

• Google Chrome versions prior to 147.0.7727.101
• Chromium-based browsers using affected codec libraries
• Desktop platforms (Windows, macOS, Linux)

Discovery Timeline

• 2026-04-15 - CVE-2026-6318 published to NVD
• 2026-04-16 - Last updated in NVD database

Technical Details for CVE-2026-6318

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a memory corruption vulnerability that occurs when a program continues to use a pointer after the memory it references has been freed. In the context of Google Chrome's Codecs component, this flaw manifests during media processing operations where complex data structures are allocated and deallocated dynamically.

The use-after-free condition creates an opportunity for attackers to manipulate program execution by controlling the contents of the freed memory region. When the vulnerable code path subsequently accesses this memory, it may read attacker-controlled data or execute attacker-supplied code, depending on how the memory has been reallocated.

While Chromium's security team rated this as medium severity, the potential for arbitrary code execution makes this a significant concern for enterprise environments. The sandboxed execution context provides some mitigation, but sandbox escapes combined with this vulnerability could lead to full system compromise.

Root Cause

The root cause lies in improper lifecycle management of memory objects within Chrome's media codec processing pipeline. During certain media decoding operations, memory associated with codec state or buffer objects may be freed while references to that memory still exist in the application. Subsequent operations that dereference these stale pointers trigger the use-after-free condition.

This type of vulnerability commonly arises in complex C++ codebases where object ownership and lifetime management is not clearly defined, particularly in asynchronous processing scenarios where multiple components may hold references to shared resources.

Attack Vector

The attack is network-based and requires user interaction—specifically, the victim must navigate to a malicious webpage containing the crafted HTML content. The attacker can embed malicious media content or codec-triggering elements within seemingly legitimate web pages or advertisements.

The exploitation flow typically involves:

1. Attacker crafts an HTML page with specific media elements designed to trigger the vulnerable code path
2. Victim visits the malicious page (via phishing, malvertising, or compromised website)
3. Chrome's codec component processes the malicious content
4. The use-after-free condition is triggered during media decoding
5. Attacker achieves code execution within the browser sandbox

Technical details regarding the specific exploitation mechanism can be found in the Chromium Issue Tracker #495996858 once the security embargo is lifted.

Detection Methods for CVE-2026-6318

Indicators of Compromise

• Unusual Chrome renderer process crashes or hangs during media playback
• Unexpected memory access patterns in Chrome processes
• Browser stability issues when loading pages with embedded media content
• Suspicious network traffic to domains serving malformed media files

Detection Strategies

• Monitor for Chrome crash reports related to codec or media components
• Implement network-level inspection for malformed media file signatures
• Deploy endpoint detection rules for suspicious memory allocation patterns in browser processes
• Utilize browser telemetry to identify pages triggering unexpected codec behavior

Monitoring Recommendations

• Enable Chrome's built-in security reporting and crash telemetry
• Monitor enterprise endpoints for Chrome version compliance below 147.0.7727.101
• Review web proxy logs for access to known malicious domains distributing exploit content
• Configure SIEM alerts for browser-related memory corruption indicators

How to Mitigate CVE-2026-6318

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.101 or later immediately
• Enable automatic Chrome updates across all enterprise endpoints
• Verify update deployment through browser version auditing
• Consider temporary restrictions on media-heavy or untrusted websites until patching is complete

Patch Information

Google has released Chrome version 147.0.7727.101 which addresses this vulnerability. The update is available through Chrome's standard update mechanism and enterprise deployment tools. Organizations should reference the Google Chrome Desktop Update announcement for complete release notes and additional security fixes included in this release.

For enterprise deployments, administrators can push the updated version through Google Admin Console, Microsoft Intune, or other endpoint management solutions.

Workarounds

• Implement strict content security policies to limit media sources to trusted origins
• Consider using browser isolation solutions for high-risk web browsing activities
• Deploy network-level filtering to block potentially malicious media content
• Enable Chrome's Site Isolation feature if not already active for additional sandboxing protection

# Verify Chrome version on Linux/macOS
google-chrome --version
# Expected output: Google Chrome 147.0.7727.101 or higher

# Enterprise deployment verification (Windows)
# Check installed version via registry
reg query "HKLM\SOFTWARE\Google\Chrome\BLBeacon" /v version