CVE-2026-19557: Google Chrome Use After Free Vulnerability

CVE-2026-19557 Overview

CVE-2026-19557 is a use-after-free vulnerability in the TabStrip component of Google Chrome on macOS. The flaw affects Chrome versions prior to 151.0.7922.137. A remote attacker who has already compromised the renderer process can leverage a crafted HTML page to potentially escape the Chrome sandbox. The issue is tracked under CWE-416 and was rated High by the Chromium security team.

Critical Impact
Successful exploitation enables a sandbox escape from a compromised renderer, allowing attacker-controlled code to break out of Chrome's isolated process boundary on macOS.

Affected Products

Google Chrome for macOS versions prior to 151.0.7922.137
Chromium-based browsers on macOS that incorporate the vulnerable TabStrip code
Chrome Stable channel on Mac before the August 2026 update

Discovery Timeline

2026-08-11 - CVE-2026-19557 published to the National Vulnerability Database
2026-08-13 - Last updated in NVD database

Technical Details for CVE-2026-19557

Vulnerability Analysis

The vulnerability resides in the TabStrip component, which manages the browser's tab UI and associated state on macOS. A use-after-free condition occurs when memory referenced by TabStrip is released while a pointer to it remains reachable. Subsequent access to the freed memory allows an attacker to influence process control flow.

Exploitation requires that the attacker first compromise the renderer process, typically through a preceding renderer bug triggered by a crafted HTML page. From that position, the TabStrip flaw becomes a stepping stone toward sandbox escape. A successful escape grants code execution in the browser process, which runs outside the renderer sandbox restrictions.

The attack requires user interaction, such as navigating to attacker-controlled content, and the attack complexity is high because it depends on chaining a prior renderer compromise.

Root Cause

The root cause is improper lifetime management of an object within the TabStrip subsystem. A reference to a heap-allocated object is retained after the object is destroyed, producing a dangling pointer that is later dereferenced. This class of bug is tracked as CWE-416: Use After Free.

Attack Vector

The attack vector is network-based delivery of a crafted HTML page. The attacker first exploits a separate flaw to gain code execution inside the renderer. Using that foothold, the attacker triggers the TabStrip use-after-free to corrupt browser-process memory and escape the sandbox. Public technical details are limited; refer to the Chromium Issue Tracker Entry and the Google Chrome Stable Update for vendor information.

Detection Methods for CVE-2026-19557

Indicators of Compromise

Chrome renderer or browser process crashes on macOS with signatures referencing TabStrip or freed heap objects
Unexpected child processes spawned by Google Chrome.app following visits to untrusted web content
macOS Unified Log entries showing Chrome sandbox violations or sandboxd denials tied to the browser process

Detection Strategies

Inventory installed Chrome versions on macOS endpoints and flag any build below 151.0.7922.137
Monitor for anomalous file writes, LaunchAgent creation, or persistence attempts originating from Chrome helper processes
Correlate browser process crash telemetry with subsequent process execution or outbound network activity

Monitoring Recommendations

Ingest macOS EndpointSecurity and browser telemetry into a centralized analytics pipeline for behavioral analysis
Alert on Chrome browser process performing unusual system calls such as posix_spawn of shells or scripting interpreters
Track outbound connections from Chrome to newly observed or low-reputation domains immediately following page loads

How to Mitigate CVE-2026-19557

Immediate Actions Required

Update Google Chrome on macOS to version 151.0.7922.137 or later through the Stable channel
Force browser restart on managed endpoints to ensure the patched binary is loaded into memory
Audit third-party Chromium-based browsers on macOS and apply vendor updates that incorporate the fix

Patch Information

Google addressed the issue in the Chrome Stable channel update announced in the Google Chrome Stable Update. Administrators should deploy Chrome 151.0.7922.137 or later on all macOS endpoints. Enterprise deployments using MDM should verify the update policy pushes the fixed version.

Workarounds

Restrict browsing to trusted sites via web content filtering until patches are deployed
Enforce Chrome enterprise policies that disable unnecessary features and require automatic updates
Isolate high-risk users behind remote browser isolation while patch rollout completes

bash

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

# Example MDM command to trigger Chrome update policy enforcement
sudo defaults write /Library/Preferences/com.google.Keystone.Agent checkInterval -int 3600