CVE-2026-6317: Google Chrome Cast Use After Free Flaw

CVE-2026-6317 Overview

CVE-2026-6317 is a use-after-free vulnerability discovered in the Cast component of Google Chrome. This memory corruption flaw exists in Chrome versions prior to 147.0.7727.101 and allows remote attackers to execute arbitrary code by luring victims to visit a specially crafted HTML page. The vulnerability stems from improper memory management in the Cast functionality, where freed memory is subsequently accessed, leading to potential arbitrary code execution.

Critical Impact

Remote attackers can achieve arbitrary code execution on affected systems by exploiting this use-after-free vulnerability through a malicious web page, potentially leading to complete system compromise.

Affected Products

• Google Chrome prior to version 147.0.7727.101 (Desktop)
• Chromium-based browsers prior to version 147.0.7727.101
• All platforms running vulnerable Chrome versions (Windows, macOS, Linux)

Discovery Timeline

• 2026-04-15 - CVE-2026-6317 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-6317

Vulnerability Analysis

This vulnerability is classified as CWE-416 (Use After Free), a dangerous memory corruption vulnerability type. Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it references has been freed. In the context of the Chrome Cast component, this flaw allows attackers to manipulate memory in ways that can redirect program execution flow.

The vulnerability requires user interaction—specifically, a victim must navigate to a malicious web page crafted by the attacker. Once triggered, the vulnerability can lead to arbitrary code execution within the context of the Chrome browser process, potentially allowing attackers to escape the browser sandbox or execute malicious payloads on the victim's system.

Root Cause

The root cause lies in improper memory lifecycle management within Chrome's Cast component. When handling certain operations related to Cast functionality, the code fails to properly track memory ownership, resulting in a scenario where:

1. Memory is allocated for a Cast-related object
2. The memory is freed during a specific operation or state change
3. A dangling pointer to the freed memory remains accessible
4. Subsequent code attempts to access or manipulate the freed memory
5. An attacker can influence what data occupies the freed memory region, enabling arbitrary code execution

Attack Vector

The attack vector for CVE-2026-6317 is network-based, requiring user interaction. An attacker must craft a malicious HTML page that triggers the use-after-free condition in the Cast component. The exploitation scenario typically involves:

The vulnerability is triggered through specially crafted HTML/JavaScript that interacts with Chrome's Cast functionality. When a victim visits the malicious page, the attacker's code can manipulate the timing and sequence of Cast-related operations to cause the use-after-free condition. By carefully controlling heap allocations, the attacker can place controlled data in the freed memory region, enabling them to hijack control flow and execute arbitrary code.

For technical details on this vulnerability, refer to the Chromium Issue Tracker Entry and the Google Chrome Releases Blog.

Detection Methods for CVE-2026-6317

Indicators of Compromise

• Unexpected Chrome crashes or instability when visiting untrusted websites
• Memory access violations or segmentation faults in Chrome processes related to Cast functionality
• Unusual child processes spawned from Chrome browser processes
• Suspicious network connections originating from Chrome after visiting unknown sites

Detection Strategies

• Monitor for Chrome versions prior to 147.0.7727.101 across the enterprise environment
• Deploy endpoint detection and response (EDR) solutions to identify exploitation attempts targeting browser memory corruption
• Implement network monitoring for connections to known malicious domains hosting exploit code
• Use browser-based security extensions that can detect and block malicious JavaScript execution patterns

Monitoring Recommendations

• Enable Chrome crash reporting and monitor for Cast-related crash signatures
• Implement application allowlisting to prevent unauthorized code execution from browser compromises
• Deploy SentinelOne Singularity Platform to detect post-exploitation activities and lateral movement attempts
• Monitor for anomalous browser behavior patterns that may indicate memory corruption exploitation

How to Mitigate CVE-2026-6317

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.101 or later immediately across all systems
• Enable automatic Chrome updates to ensure timely patching of future vulnerabilities
• Restrict access to untrusted websites through web filtering solutions until patching is complete
• Consider temporarily disabling Cast functionality in enterprise environments if immediate patching is not feasible

Patch Information

Google has addressed this vulnerability in Chrome version 147.0.7727.101. The security update was announced via the Google Chrome Releases Blog. Organizations should prioritize deployment of this update across all managed endpoints.

To verify the installed Chrome version, navigate to chrome://settings/help or check via command line. Enterprise administrators can use Google's Admin console or third-party patch management solutions to deploy updates at scale.

Workarounds

• Use alternative browsers for high-risk browsing activities until Chrome is updated
• Implement strict Content Security Policy (CSP) headers on internal web applications
• Deploy browser isolation solutions to contain potential exploitation attempts
• Disable the Cast feature via Chrome enterprise policies if feasible in your environment

# Chrome enterprise policy to disable Cast (Windows Registry)
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# EnableMediaRouter = 0

# For Linux/macOS managed Chrome deployments:
# Set the following in the managed preferences:
# "EnableMediaRouter": false

# Verify Chrome version via command line (Linux/macOS):
google-chrome --version
# Expected output: Google Chrome 147.0.7727.101 or higher