CVE-2026-106240: Google Chrome V8 RCE Vulnerability

CVE-2026-106240 Overview

CVE-2026-106240 is a type confusion vulnerability in the V8 JavaScript engine used by Google Chrome. The flaw affects Chrome versions prior to 155.0.8059.39 and allows a remote attacker to execute arbitrary code inside the Chrome sandbox through a crafted HTML page. Google rated the Chromium security severity as High. Exploitation requires user interaction, specifically visiting an attacker-controlled page. The vulnerability is tracked under CWE-843: Access of Resource Using Incompatible Type.

Critical Impact
A remote attacker can execute arbitrary code inside the Chrome sandbox by luring a user to a malicious HTML page, providing a foothold for further exploitation chains.

Affected Products

Google Chrome versions prior to 155.0.8059.39
Chromium-based browsers that embed vulnerable V8 builds
Desktop Chrome Stable channel across Windows, macOS, and Linux

Discovery Timeline

2026-10-06 - CVE-2026-106240 published to NVD
2026-10-07 - Last updated in NVD database

Technical Details for CVE-2026-106240

Vulnerability Analysis

The vulnerability is a type confusion in V8, the JavaScript and WebAssembly engine inside Chromium. Type confusion occurs when code operates on a memory object while assuming it has a type different from the one actually allocated. In V8, this class of bug typically arises in the optimizing compiler (TurboFan or Maglev) when speculative assumptions about object shapes, maps, or element kinds are not correctly invalidated. The resulting mismatch lets attacker-controlled JavaScript read or write memory outside intended object boundaries, which can be shaped into an arbitrary read/write primitive and ultimately code execution within the renderer sandbox.

Successful exploitation yields code execution confined to the Chrome sandbox. Full compromise of the host typically requires chaining this bug with a separate sandbox escape. Technical details are tracked in Chromium Issue #567177599.

Root Cause

The root cause is incorrect type handling in V8, classified as CWE-843. JavaScript operations on an object are performed under the wrong type assumption, which breaks V8's memory safety invariants. Google has not publicly released the exact code location while patch adoption is ongoing.

Attack Vector

The attack vector is network based with required user interaction. An attacker hosts a crafted HTML page containing JavaScript designed to trigger the V8 type confusion. When a user navigates to the page, the engine executes the exploit and the attacker gains code execution inside the renderer process. Delivery channels include malicious ads, phishing links, compromised websites, and injected iframes on trusted sites.

No verified public proof-of-concept code is available. Refer to the Chrome Releases advisory for vendor guidance.

Detection Methods for CVE-2026-106240

Indicators of Compromise

Chrome renderer process crashes with signatures referencing V8, TurboFan, or Maglev components
Unexpected child processes spawned by chrome.exe or the renderer helper following web navigation
Outbound connections from the browser process to newly registered or low-reputation domains
Browser instances running versions below 155.0.8059.39 after a scheduled update window

Detection Strategies

Inventory installed Chrome versions across managed endpoints and flag any build earlier than 155.0.8059.39
Alert on anomalous process trees where the Chrome renderer launches shells, script interpreters, or LOLBins
Correlate browser crash telemetry with network activity to identify drive-by exploitation attempts

Monitoring Recommendations

Monitor EDR telemetry for in-memory execution patterns originating from browser renderer processes
Track DNS and HTTP requests from endpoints to domains flagged by threat intelligence as exploit kit infrastructure
Review browser update compliance reports daily until all endpoints are on a patched build

How to Mitigate CVE-2026-106240

Immediate Actions Required

Update Google Chrome to version 155.0.8059.39 or later on all desktop endpoints
Restart browser sessions after patch deployment to ensure the vulnerable V8 build is unloaded from memory
Verify that Chromium-based browsers (Edge, Brave, Opera, Vivaldi) have incorporated the upstream V8 fix

Patch Information

Google released the fix in the Stable Channel update documented in the Chrome Releases blog post. Enterprises using managed Chrome deployments should push the update through Google Admin, Group Policy, or their endpoint management platform. Confirm the installed version by navigating to chrome://settings/help.

Workarounds

Enforce browser auto-update policies and block launch of outdated Chrome versions through application control
Restrict access to untrusted websites using DNS filtering and secure web gateway policies
Enable Site Isolation and Enhanced Safe Browsing to reduce the exploitation surface for crafted HTML pages
Encourage users to avoid clicking links from unknown senders until patch rollout completes

bash

# Verify Chrome version on Linux endpoints
google-chrome --version

# Windows: force update via registry policy
reg add "HKLM\SOFTWARE\Policies\Google\Update" /v UpdateDefault /t REG_DWORD /d 1 /f
reg add "HKLM\SOFTWARE\Policies\Google\Update" /v AutoUpdateCheckPeriodMinutes /t REG_DWORD /d 60 /f