CVE-2026-11269: Google Chrome RCE Vulnerability

CVE-2026-11269 Overview

CVE-2026-11269 is a high-severity vulnerability in the Extensions component of Google Chrome prior to version 149.0.7827.53. The flaw stems from an inappropriate implementation that allows an attacker in a privileged network position to execute arbitrary code inside the Chrome sandbox via a crafted Chrome Extension. The issue is tracked under [CWE-829: Inclusion of Functionality from Untrusted Control Sphere]. Google rated the underlying Chromium security severity as Low, but the assigned CVSS score reflects high impact across confidentiality, integrity, and availability when exploitation succeeds.

Critical Impact
Successful exploitation enables arbitrary code execution within the Chrome sandbox on Windows, macOS, and Linux endpoints running vulnerable Chrome versions.

Affected Products

Google Chrome versions prior to 149.0.7827.53
Chrome on Microsoft Windows, Apple macOS, and Linux desktop builds
Chromium-based browsers using the affected Extensions implementation

Discovery Timeline

2026-06-05 - CVE-2026-11269 published to the National Vulnerability Database
2026-06-08 - Last updated in NVD database

Technical Details for CVE-2026-11269

Vulnerability Analysis

The vulnerability resides in how Google Chrome's Extensions subsystem handles content sourced from untrusted control spheres. An attacker positioned on an adjacent network can deliver or influence a crafted Chrome Extension whose components are loaded by the browser in a manner the developers did not intend. The improper handling permits attacker-controlled logic to execute arbitrary code inside the Chrome sandbox process. While the sandbox confines the resulting execution, code running inside it can interact with extension APIs, browsing data, and other in-sandbox resources, providing a useful primitive for follow-on attacks.

Exploitation requires user interaction and a high-complexity setup, including the privileged adjacent network position needed to influence extension delivery or update channels. The vendor advisory tracks the fix in the Stable Channel Update for Desktop, with implementation details available in the Chromium Issue Tracker Entry.

Root Cause

The root cause is an inappropriate implementation within the Extensions component, classified under [CWE-829]. Chrome incorporates extension-supplied functionality without sufficient validation of the source or content, allowing a crafted extension to introduce behavior that bypasses intended security boundaries. This pattern is characteristic of trust boundary violations in browser extension architectures.

Attack Vector

The attack vector is Adjacent Network, meaning the attacker must occupy a privileged position on the same logical network segment as the victim. The attacker leverages this position to deliver or substitute a crafted extension, and the victim must perform an interaction with the malicious content. Once triggered, the exploit yields arbitrary code execution constrained to the Chrome sandbox.

No public proof-of-concept code, exploit kit entry, or CISA KEV listing exists for this CVE at the time of writing. The EPSS probability of 0.008% indicates low predicted exploitation likelihood in the near term.

Detection Methods for CVE-2026-11269

Indicators of Compromise

Chrome processes spawning unexpected child processes or making anomalous network connections shortly after extension installation or update.
Newly installed or recently updated Chrome Extensions from unverified sources, particularly those loaded outside the Chrome Web Store.
Modifications to the Chrome Extensions directory on disk that do not correlate with user-initiated installs.

Detection Strategies

Inventory installed Chrome Extensions across managed endpoints and flag any extension that is sideloaded, developer-mode, or absent from an approved allowlist.
Monitor Chrome version telemetry and alert on hosts running versions below 149.0.7827.53.
Inspect network telemetry for adjacent-network conditions such as ARP spoofing, rogue DHCP, or captive portal anomalies that could enable extension tampering.

Monitoring Recommendations

Forward browser process telemetry and extension load events to a centralized analytics pipeline for correlation with network anomalies.
Track Chromium auto-update success rates and investigate endpoints where the Stable channel update has not applied.
Review enterprise policy logs for changes to ExtensionInstallSources, ExtensionInstallForcelist, and ExtensionAllowedTypes.

How to Mitigate CVE-2026-11269

Immediate Actions Required

Update Google Chrome to version 149.0.7827.53 or later on all Windows, macOS, and Linux endpoints.
Verify that Chrome's automatic update mechanism is functioning and that managed devices have rebooted Chrome to apply the patched binary.
Audit installed extensions and remove any that are unverified, sideloaded, or no longer required.

Patch Information

Google released the fix in the Chrome Stable channel update documented at the Stable Channel Update for Desktop. Administrators should confirm deployment of Chrome 149.0.7827.53 or later. Technical change details are referenced in the Chromium Issue Tracker Entry.

Workarounds

Restrict extension installation to a vetted allowlist using the ExtensionInstallForcelist and ExtensionInstallBlocklist enterprise policies.
Disable developer mode and block sideloading by setting ExtensionInstallSources to an empty or strictly controlled list.
Enforce network hygiene controls such as 802.1X, ARP inspection, and DHCP snooping to reduce the feasibility of an adjacent-network attacker position.

bash

# Configuration example: Chrome enterprise policy to constrain extensions (Linux managed policy JSON)
# Path: /etc/opt/chrome/policies/managed/extensions.json
{
  "ExtensionInstallBlocklist": ["*"],
  "ExtensionInstallForcelist": [
    "<approved-extension-id>;https://clients2.google.com/service/update2/crx"
  ],
  "ExtensionAllowedTypes": ["extension", "theme"],
  "DeveloperToolsAvailability": 2
}