CVE-2026-11238: Google Chrome Information Disclosure Flaw

CVE-2026-11238 Overview

CVE-2026-11238 is an information disclosure vulnerability in the DevTools component of Google Chrome versions prior to 149.0.7827.53. The flaw stems from an inappropriate implementation that allows a malicious Chrome extension to read potentially sensitive data from process memory. Exploitation requires user interaction in the form of installing an attacker-controlled extension. Google classified the underlying Chromium severity as Low, while the NVD assigned a medium rating reflecting the confidentiality impact on browser process memory. The issue is tracked under [CWE-306] (Missing Authentication for Critical Function) and was addressed in the Chrome stable channel update for desktop.

Critical Impact
A crafted Chrome Extension can extract sensitive information from browser process memory through DevTools, potentially exposing credentials, session tokens, or other secrets handled by the browser.

Affected Products

Google Chrome prior to 149.0.7827.53 on Microsoft Windows
Google Chrome prior to 149.0.7827.53 on Apple macOS
Google Chrome prior to 149.0.7827.53 on Linux

Discovery Timeline

2026-06-05 - CVE-2026-11238 published to NVD
2026-06-05 - Last updated in NVD database
2026-06 - Google releases stable channel update for desktop addressing the issue

Technical Details for CVE-2026-11238

Vulnerability Analysis

The vulnerability resides in Chrome DevTools, the developer tooling subsystem that exposes inspection and debugging primitives to extensions through the chrome.debugger and DevTools Protocol APIs. An inappropriate implementation in this surface fails to enforce proper boundaries between extension-supplied requests and privileged process memory regions. As a result, a malicious extension can craft DevTools interactions that return contents of process memory not intended for extension access.

The weakness maps to [CWE-306], indicating that a critical function lacks the authentication or authorization check needed to confine extension access. Because Chrome extensions run with elevated privileges relative to web content, the missing check converts a normal API surface into a memory disclosure primitive. The attack does not yield code execution or integrity loss but does compromise confidentiality of in-process data.

Root Cause

The root cause is missing or insufficient validation in a DevTools code path reachable from the extension API. The code path returns or exposes data sourced from process memory without verifying that the requesting extension is entitled to that data. Attack complexity is rated high because exploitation depends on specific runtime conditions and convincing the user to install the malicious extension.

Attack Vector

Exploitation requires the attacker to publish or sideload a Chrome extension and persuade a victim to install it. Once installed, the extension issues crafted DevTools calls that trigger the inappropriate implementation and harvest memory contents. The attack is network-reachable in the sense that the extension can be delivered through web channels, but no remote code execution is achieved. Information harvested can include session cookies, OAuth tokens, cached form values, or fragments of pages rendered in the browser.

No public proof-of-concept code is available for CVE-2026-11238. Technical detail is restricted to the Chromium Issue Tracker Entry and the Google Chrome Update Announcement.

Detection Methods for CVE-2026-11238

Indicators of Compromise

Chrome extensions requesting the debugger permission or programmatic DevTools access without a clear developer-tooling use case.
Outbound network connections from extension background service workers to unfamiliar domains carrying base64 or compressed payloads.
Chrome processes running versions earlier than 149.0.7827.53 in managed fleets after the patch release window.

Detection Strategies

Inventory installed Chrome extensions across endpoints and flag any that declare debugger, devtools_page, or broad host permissions.
Correlate extension installation events with subsequent anomalous browser child-process behavior or unusual data egress.
Track Chrome version telemetry and alert on hosts running builds below 149.0.7827.53.

Monitoring Recommendations

Enable Chrome enterprise reporting (ExtensionInstallReportingEnabled) to capture extension installs, updates, and permission changes.
Monitor endpoint process telemetry for chrome.exe child processes spawning with --remote-debugging-port or similar DevTools flags.
Review extension store ratings and publisher reputation as part of routine browser hygiene checks.

How to Mitigate CVE-2026-11238

Immediate Actions Required

Update Google Chrome to version 149.0.7827.53 or later on all Windows, macOS, and Linux endpoints.
Audit installed extensions and remove any that are unsigned, unmaintained, or request debugger permissions without justification.
Enforce an extension allowlist through enterprise policy to block installation of unvetted extensions.

Patch Information

Google released the fix in the Chrome stable channel update for desktop. The fixed version is 149.0.7827.53. Refer to the Google Chrome Update Announcement for release details and to the Chromium Issue Tracker Entry for issue tracking metadata. Chrome auto-update should deliver the patch on next browser restart for users on the stable channel.

Workarounds

Use Chrome enterprise policy ExtensionInstallBlocklist set to * combined with an explicit ExtensionInstallAllowlist to restrict extensions to vetted IDs.
Disable extensions that request debugger API access until the browser is patched.
Apply DeveloperToolsAvailability policy to restrict DevTools access where developer tooling is not required.

bash

# Configuration example - Chrome enterprise policy (Windows registry)
reg add "HKLM\Software\Policies\Google\Chrome" /v ExtensionInstallBlocklist /t REG_SZ /d "*" /f
reg add "HKLM\Software\Policies\Google\Chrome\ExtensionInstallAllowlist" /v 1 /t REG_SZ /d "<approved-extension-id>" /f
reg add "HKLM\Software\Policies\Google\Chrome" /v DeveloperToolsAvailability /t REG_DWORD /d 2 /f