CVE-2026-13903: Google Chrome Privilege Escalation Flaw

CVE-2026-13903 Overview

CVE-2026-13903 is a privilege escalation vulnerability in the Bluetooth component of Google Chrome. The flaw stems from insufficient policy enforcement [CWE-602], allowing a remote attacker to escalate privileges through a crafted HTML page. The issue affects all versions of Chrome prior to 150.0.7871.47 on desktop platforms. Successful exploitation requires user interaction, such as visiting a malicious website. Google addressed the flaw in the Stable Channel update for desktop released in June 2026.

Critical Impact
A remote attacker can achieve privilege escalation via a crafted HTML page, gaining elevated access to browser resources and potentially bypassing Bluetooth API restrictions.

Affected Products

Google Chrome for Desktop versions prior to 150.0.7871.47
Chromium-based browsers sharing the same Bluetooth component code
All operating systems supported by Chrome desktop (Windows, macOS, Linux)

Discovery Timeline

2026-06-30 - CVE-2026-13903 published to the National Vulnerability Database (NVD)
2026-07-02 - Last updated in the NVD database

Technical Details for CVE-2026-13903

Vulnerability Analysis

The vulnerability originates in Chrome's Bluetooth subsystem, which exposes device access to web content through the Web Bluetooth API. Chrome enforces policies to restrict which origins can enumerate, pair with, or communicate with Bluetooth devices. This CVE reflects a failure in that policy enforcement layer, mapped to [CWE-602] Client-Side Enforcement of Server-Side Security.

When policy checks are incomplete or occur on the client side without proper validation, an attacker can craft HTML content that induces the browser to take actions the user did not authorize. In this case, the outcome is privilege escalation within the browser's security model. The attack requires network access to deliver the crafted page and user interaction to trigger the vulnerable code path.

Root Cause

The root cause is insufficient enforcement of security policies governing Bluetooth operations. Client-side policy checks that should have blocked unauthorized operations were either absent, bypassable, or incorrectly scoped. This class of flaw commonly appears when trust decisions are made in code paths that attacker-controlled input can influence.

Attack Vector

Exploitation proceeds through a standard web delivery chain. An attacker hosts a crafted HTML page on a controlled domain or injects the payload into a compromised site. When a victim running a vulnerable Chrome build loads the page and completes the required interaction, the malicious script invokes Bluetooth functionality in a way that circumvents the intended policy checks. The outcome is elevated privileges within the browser context, which can be chained with additional flaws for broader compromise.

Google has not disclosed exploitation details. Refer to the Chromium Issue Tracking entry for available technical context.

Detection Methods for CVE-2026-13903

Indicators of Compromise

Chrome processes making unexpected Bluetooth API calls or spawning child processes after loading untrusted web content
Browser telemetry showing Web Bluetooth permission prompts on domains that do not legitimately use Bluetooth features
Outbound connections from Chrome renderer processes to newly registered or low-reputation domains hosting HTML payloads

Detection Strategies

Inventory endpoints for Chrome versions below 150.0.7871.47 using software asset management or EDR telemetry
Monitor Chrome update status through enterprise browser management consoles and flag hosts on outdated builds
Correlate web proxy logs with Chrome process activity to identify suspicious HTML content delivery followed by anomalous browser behavior

Monitoring Recommendations

Enable browser security event logging and forward events to a centralized SIEM for correlation with endpoint telemetry
Track Web Bluetooth permission grants across the fleet, alerting when permissions are granted to unusual origins
Watch for post-exploitation indicators such as unexpected process creation, file writes, or persistence attempts originating from browser processes

How to Mitigate CVE-2026-13903

Immediate Actions Required

Update Google Chrome to version 150.0.7871.47 or later on all desktop endpoints without delay
Force browser restarts through group policy or MDM to ensure the patched binary is loaded into memory
Verify Chromium-based browsers in the environment (Edge, Brave, Opera, Vivaldi) have absorbed the upstream fix before considering remediation complete

Patch Information

Google released the fix in the Stable Channel update for desktop. See the Google Chrome Update Announcement for the official advisory. The fix is included in Chrome 150.0.7871.47 and later builds. Administrators managing Chrome through enterprise policy should confirm the TargetVersionPrefix policy is not pinning devices to an older major version.

Workarounds

Disable the Web Bluetooth API through the DefaultWebBluetoothGuardSetting enterprise policy set to 2 (block) until patching is complete
Restrict Bluetooth-capable web origins using the WebBluetoothAllowedForUrls policy to limit exposure to trusted domains only
Instruct users to avoid interacting with Bluetooth prompts from unknown websites and to report unexpected permission requests

bash

# Configuration example: enforce Chrome update and disable Web Bluetooth via policy (Linux managed_policies)
# /etc/opt/chrome/policies/managed/bluetooth_hardening.json
{
  "DefaultWebBluetoothGuardSetting": 2,
  "TargetVersionPrefix": "150.0.7871.47",
  "RelaunchNotification": 2,
  "RelaunchNotificationPeriod": 3600000
}