CVE-2026-11242: Google Chrome Information Disclosure Flaw

CVE-2026-11242 Overview

CVE-2026-11242 is an input validation vulnerability in the Plugins component of Google Chrome prior to version 149.0.7827.53. The flaw allows a remote attacker who has already compromised the renderer process to leak cross-origin data through a crafted HTML page. Google classifies the Chromium security severity as Low, while the National Vulnerability Database scores it higher due to confidentiality impact across the network attack surface. The vulnerability is tracked under [CWE-20] (Improper Input Validation) and affects Chrome on Windows, macOS, and Linux.

Critical Impact
An attacker controlling a compromised renderer can bypass the same-origin policy and exfiltrate data belonging to other web origins.

Affected Products

Google Chrome prior to 149.0.7827.53
Chrome on Microsoft Windows, Apple macOS, and Linux
Chromium-based browsers incorporating the affected Plugins code

Discovery Timeline

2026-06-05 - CVE-2026-11242 published to NVD
2026-06-05 - Last updated in NVD database

Technical Details for CVE-2026-11242

Vulnerability Analysis

The vulnerability resides in Chrome's Plugins subsystem, where untrusted input received from a renderer process is not sufficiently validated before being acted on by more privileged browser code paths. An attacker who has already gained code execution within the sandboxed renderer can craft messages or HTML content that drive the plugin handling logic into returning data belonging to a different origin. This effectively bypasses the same-origin policy, which is a core browser security boundary intended to isolate content from different web origins.

The issue requires a prior compromise of the renderer process, meaning the attacker must chain this flaw with a separate vulnerability such as a renderer remote code execution or memory corruption bug. Once chained, the attacker can read sensitive data including authenticated session content, tokens embedded in cross-origin responses, or DOM state from unrelated sites loaded in the same browser instance.

Root Cause

The root cause is improper input validation [CWE-20] in the Plugins component. Data flowing from the lower-privileged renderer is trusted by plugin handling code without enforcing origin checks or schema validation. This allows attacker-controlled inputs to influence which data the browser surfaces back to the renderer.

Attack Vector

Exploitation is network-based and requires no user interaction beyond the attacker having already compromised the renderer. The attacker hosts a crafted HTML page that, when combined with renderer compromise, triggers the malformed plugin interaction. Confidentiality is impacted, while integrity and availability are not. See the Chromium Issue Tracker entry for technical context.

No public proof-of-concept code is available, and no verified exploitation samples have been released. A prose description is provided in lieu of synthetic exploit code.

Detection Methods for CVE-2026-11242

Indicators of Compromise

Chrome processes running versions earlier than 149.0.7827.53 on managed endpoints
Unexpected child process spawns from chrome.exe or renderer crashes correlated with browsing activity
Outbound network connections from browser processes to unfamiliar domains immediately after page loads

Detection Strategies

Inventory browser versions across the fleet and flag installations below 149.0.7827.53 for remediation
Monitor renderer process crash dumps and sandbox escape telemetry, since this vulnerability requires a prior renderer compromise
Correlate web proxy logs with endpoint telemetry to identify users visiting suspicious pages tied to known Chrome exploitation chains

Monitoring Recommendations

Enable enterprise reporting in Chrome to forward version and extension data to a central log store
Ingest browser telemetry into a SIEM and create alerts for outdated Chrome versions on production endpoints
Track Google Chrome release notes and Chromium issue tracker updates for related plugin-component advisories

How to Mitigate CVE-2026-11242

Immediate Actions Required

Update Google Chrome to version 149.0.7827.53 or later on all Windows, macOS, and Linux endpoints
Verify that auto-update is enabled and not blocked by group policy or proxy configuration
Restart Chrome on user workstations to ensure the patched binaries are loaded into memory

Patch Information

Google released the fix in the Chrome Stable channel at version 149.0.7827.53. Refer to the Google Chrome Stable Channel Update announcement for the full advisory. Chromium-based browsers should apply the corresponding upstream patch once vendors integrate it.

Workarounds

No vendor-supplied workaround exists; upgrading to the patched version is the only supported remediation
Restrict use of unnecessary browser plugins through enterprise policy to reduce the attack surface
Apply strict Content Security Policy and site isolation settings to limit cross-origin data exposure

bash

# Verify installed Chrome version on Windows
reg query "HKLM\Software\Google\Update\Clients\{8A69D345-D564-463C-AFF1-A69D9E530F96}" /v pv

# Verify installed Chrome version on macOS
defaults read /Applications/Google\ Chrome.app/Contents/Info CFBundleShortVersionString

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