CVE-2026-11246: Google Chrome Auth Bypass Vulnerability

CVE-2026-11246 Overview

CVE-2026-11246 is an input validation flaw in the IndexedDB component of Google Chrome prior to version 149.0.7827.53. The vulnerability allows a remote attacker who has already compromised the renderer process to bypass the same-origin policy by serving a crafted HTML page. Successful exploitation undermines a core browser security boundary that isolates content between web origins.

The issue is tracked under [CWE-20] (Improper Input Validation) and was addressed in the Chrome Stable channel update for desktop. Chromium classifies the internal severity as Low, while the NVD-assigned CVSS 3.1 score reflects a higher impact on integrity when chained with a renderer compromise.

Critical Impact
An attacker chaining this bug with a renderer exploit can read or modify data belonging to other web origins, breaking site isolation guarantees.

Affected Products

Google Chrome versions prior to 149.0.7827.53
Chrome desktop on Microsoft Windows
Chrome desktop on Apple macOS and Linux

Discovery Timeline

2026-06-05 - CVE-2026-11246 published to NVD
2026-06-05 - Last updated in NVD database
2026-06 - Google releases Chrome Stable channel update for desktop addressing the issue

Technical Details for CVE-2026-11246

Vulnerability Analysis

The vulnerability resides in IndexedDB, the browser's transactional client-side storage API for structured data. IndexedDB enforces origin-based access controls so that scripts from one origin cannot read or write data persisted by another. CVE-2026-11246 stems from insufficient validation of untrusted input crossing the renderer-to-browser boundary, which allows an attacker to influence how origin checks are evaluated.

Exploitation requires the attacker to have already compromised the renderer process. From that position, a crafted HTML page can drive IndexedDB operations that the browser process accepts without correctly validating the requesting origin. The result is a same-origin policy bypass, granting access to stored data belonging to other origins.

The flaw does not enable code execution on its own and requires user interaction with the malicious page. Its value to an attacker is as a privilege-escalation primitive that extends a renderer compromise into cross-origin data theft or tampering.

Root Cause

The root cause is improper input validation [CWE-20] in IndexedDB message handling. The browser process trusts certain fields supplied by the renderer when arbitrating storage requests. A compromised renderer can supply values that no honest renderer would produce, defeating origin enforcement.

Attack Vector

The attack vector is network-based and requires user interaction to load a crafted page. The attacker must first achieve code execution in the renderer through a separate vulnerability, then deliver IndexedDB payloads that exercise the validation gap to reach data scoped to other origins.

No public proof-of-concept code is available for this issue. Technical specifics are tracked in the Chromium Issue Tracker #497660733.

Detection Methods for CVE-2026-11246

Indicators of Compromise

Chrome processes at versions earlier than 149.0.7827.53 loading untrusted content
Unexpected IndexedDB database files appearing under user profile directories that do not correspond to sites the user visited
Renderer process crashes or sandbox anomalies preceding cross-origin data access patterns

Detection Strategies

Inventory installed Chrome versions across the fleet and flag instances below 149.0.7827.53 for remediation tracking
Correlate browser process telemetry with outbound traffic to newly observed domains hosting heavily obfuscated JavaScript or WebAssembly
Hunt for child-process and sandbox escape behaviors originating from chrome.exe renderer processes, which are typically the precursor required to reach this bug

Monitoring Recommendations

Enable endpoint logging for browser process trees, command lines, and module loads
Alert on Chrome renderer processes spawning unusual child processes or writing to non-profile paths
Track Chrome update status as a managed configuration item and report drift to the security team

How to Mitigate CVE-2026-11246

Immediate Actions Required

Update Google Chrome to version 149.0.7827.53 or later on Windows, macOS, and Linux endpoints
Force-restart Chrome after deployment so the patched binary is loaded by all user sessions
Verify enterprise update channels (Google Update, package managers, MDM) are delivering the stable build

Patch Information

Google addressed CVE-2026-11246 in the Chrome Stable channel update for desktop. Administrators should consult the Google Chrome Stable Update advisory and confirm clients are running 149.0.7827.53 or newer. Tracking details are available in Chromium Issue Tracker #497660733.

Workarounds

Restrict browsing to trusted sites via enterprise policy until patches are deployed
Apply the SitePerProcess enterprise policy to maximize site isolation defenses against renderer compromise
Disable or restrict third-party extensions that can broaden the renderer attack surface

bash

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

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

# Enforce site isolation via Chrome enterprise policy (Linux example)
cat <<'EOF' > /etc/opt/chrome/policies/managed/site_isolation.json
{
  "SitePerProcess": true,
  "IsolateOrigins": "https://*"
}
EOF