CVE-2026-5877: Google Chrome Use After Free Vulnerability

CVE-2026-5877 Overview

CVE-2026-5877 is a Use After Free vulnerability affecting the Navigation component in Google Chrome versions prior to 147.0.7727.55. This memory corruption flaw allows a remote attacker to execute arbitrary code inside a sandbox by enticing a victim to visit a crafted HTML page. The vulnerability stems from improper memory handling in Chrome's navigation subsystem, where freed memory can be referenced after deallocation, potentially allowing attackers to manipulate program execution flow.

Critical Impact

Remote attackers can achieve arbitrary code execution within the Chrome sandbox by exploiting this Use After Free vulnerability through specially crafted web content.

Affected Products

• Google Chrome versions prior to 147.0.7727.55
• Chromium-based browsers using affected Navigation component code

Discovery Timeline

• 2026-04-08 - CVE-2026-5877 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-5877

Vulnerability Analysis

This vulnerability is classified under CWE-416 (Use After Free), a memory corruption class 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 Navigation component, this flaw can be triggered when processing specially crafted HTML content.

Use After Free vulnerabilities in browser navigation components are particularly dangerous because navigation operations are fundamental to web browsing. The Navigation component handles page transitions, history management, and URL processing—all areas that process untrusted input from web content. When memory is freed but pointers to that memory remain in use, an attacker can potentially allocate new objects in the freed memory space and manipulate the program's behavior.

While Chromium rates this as a "Medium" severity issue, the potential for arbitrary code execution—even within a sandbox—presents significant risk. Sandbox escapes, though requiring additional vulnerabilities, can chain with such flaws to achieve full system compromise.

Root Cause

The root cause is improper memory lifecycle management in Chrome's Navigation component. During certain navigation operations, memory objects are deallocated while references to those objects persist in other parts of the codebase. When these dangling pointers are subsequently dereferenced, the program accesses memory that may have been reallocated for different purposes, leading to undefined behavior that attackers can exploit.

Attack Vector

The attack vector involves a remote attacker hosting or injecting malicious HTML content designed to trigger the vulnerable code path in Chrome's Navigation component. The exploitation scenario typically follows these steps:

1. An attacker crafts a malicious HTML page containing JavaScript or DOM structures that manipulate navigation state
2. A victim visits the malicious page or is redirected to it
3. The crafted content triggers the vulnerable navigation code path, causing the Use After Free condition
4. The attacker's payload manipulates the freed memory to achieve code execution within the browser sandbox

The attack requires user interaction (visiting the malicious page) but no additional privileges. The exploitation occurs entirely within the browser's rendering context.

Detection Methods for CVE-2026-5877

Indicators of Compromise

• Unexpected browser crashes or instability during navigation operations
• Memory corruption signatures in Chrome crash dumps referencing navigation-related components
• Unusual network requests following visits to suspicious websites
• Browser process spawning unexpected child processes

Detection Strategies

• Monitor for Chrome crash reports indicating navigation component failures
• Deploy endpoint detection rules that identify suspicious HTML/JavaScript patterns targeting navigation APIs
• Use browser-based security extensions to analyze page content for known exploit patterns
• Implement network monitoring to detect connections to known exploit delivery infrastructure

Monitoring Recommendations

• Enable Chrome's built-in crash reporting to identify potential exploitation attempts
• Review endpoint detection logs for Chrome memory access violations
• Monitor browser extension telemetry for navigation anomalies
• Maintain visibility into browser update status across managed endpoints

How to Mitigate CVE-2026-5877

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.55 or later immediately
• Enable automatic updates for Chrome to receive future security patches
• Consider restricting access to untrusted websites until patching is complete
• Deploy endpoint protection solutions capable of detecting exploit attempts

Patch Information

Google has released Chrome version 147.0.7727.55 to address this vulnerability. The fix implements proper memory lifecycle management in the Navigation component to prevent Use After Free conditions. Organizations should prioritize updating all Chrome installations to this version or later.

For detailed information about this update, refer to the Google Chrome Update Advisory. Additional technical details may be available in the Chromium Issue Tracker Entry.

Workarounds

• Limit browsing to trusted websites until patches can be applied
• Use browser isolation solutions to contain potential exploitation
• Enable Chrome's Site Isolation feature for additional protection
• Consider using network-level filtering to block known malicious domains

Organizations with managed Chrome deployments should use Chrome Enterprise policies to enforce automatic updates and restrict navigation to untrusted content where feasible.