CVE-2026-14057: Google Chrome Auth Bypass Vulnerability

CVE-2026-14057 Overview

CVE-2026-14057 is a same-origin policy bypass in the Federated Credential Management (FedCM) implementation of Google Chrome. The flaw affects Chrome versions prior to 150.0.7871.47. A remote attacker can exploit the issue by convincing a user to visit a crafted HTML page, then leverage the FedCM component to bypass same-origin restrictions. The Chromium project classifies the underlying security severity as Low, and the NVD assigns a CVSS score of 4.3. The vulnerability is tracked under CWE-346: Origin Validation Error.

Critical Impact
Successful exploitation lets a remote attacker bypass same-origin policy enforcement in FedCM, exposing cross-origin data that browsers otherwise isolate between web contexts.

Affected Products

Google Chrome versions prior to 150.0.7871.47
Chromium-based browsers embedding vulnerable FedCM code
Desktop Chrome Stable channel builds preceding the June 2026 update

Discovery Timeline

2026-06-30 - CVE-2026-14057 published to NVD
2026-07-01 - Last updated in NVD database

Technical Details for CVE-2026-14057

Vulnerability Analysis

The vulnerability resides in Chrome's FedCM (Federated Credential Management) subsystem. FedCM is a browser API that mediates federated sign-in flows between identity providers and relying parties without relying on third-party cookies. The implementation fails to correctly enforce the same-origin policy under certain conditions triggered by a crafted HTML page.

Because FedCM handles cross-origin identity assertions, any weakness in origin validation directly undermines the isolation boundaries between web origins. An attacker who lures a user to a malicious page can invoke FedCM flows in a way that leaks or manipulates data across origin boundaries. User interaction is required, which limits mass exploitation but does not prevent targeted attacks through phishing or malvertising.

Root Cause

The root cause is an origin validation error [CWE-346] within FedCM's request handling logic. The component does not adequately verify that requests and responses associate with the expected origin before granting access to resources or credential material. This inappropriate implementation allows a crafted page to trick FedCM into treating cross-origin interactions as same-origin.

Attack Vector

Exploitation occurs over the network with low complexity and no privileges required, but the victim must interact with an attacker-controlled page. The attacker hosts a crafted HTML document that invokes FedCM APIs with parameters that abuse the flawed origin checks. Once the user loads the page, the browser processes the malicious FedCM flow and exposes information that same-origin policy should protect. No verified proof-of-concept code is publicly available for CVE-2026-14057. Refer to the Chromium Issue Tracker #502212647 for developer-level context once the entry is unrestricted.

Detection Methods for CVE-2026-14057

Indicators of Compromise

Chrome browser processes reporting versions below 150.0.7871.47 in enterprise inventory data
Outbound requests to unfamiliar identity provider endpoints originating from user browsers immediately after visiting untrusted pages
Web server logs showing FedCM-related endpoints (/.well-known/web-identity) being fetched by clients from unexpected referrers

Detection Strategies

Inventory endpoint browser versions and flag hosts running Chrome builds prior to 150.0.7871.47
Monitor browser telemetry and proxy logs for anomalous FedCM API invocations, particularly cross-origin credential requests
Correlate user visits to newly registered or low-reputation domains with subsequent authentication-related network activity

Monitoring Recommendations

Ingest browser version telemetry into a centralized data lake for continuous vulnerability posture assessment
Alert on Chrome installations that fall behind the current Stable channel release for more than seven days
Track EPSS shifts for CVE-2026-14057 (currently 0.181%, percentile 7.907) to reprioritize response if exploitability rises

How to Mitigate CVE-2026-14057

Immediate Actions Required

Update Google Chrome to version 150.0.7871.47 or later on all managed endpoints
Force-restart Chrome after deployment so the patched binary takes effect for active user sessions
Verify Chromium-derived browsers (Edge, Brave, Opera, Vivaldi) have absorbed the upstream FedCM fix

Patch Information

Google addressed CVE-2026-14057 in the Chrome Stable channel update to 150.0.7871.47. Deployment details are published in the Google Chrome Stable Update announcement. Enterprises using managed Chrome deployments should push the update via group policy, MDM, or their configuration management platform.

Workarounds

Disable FedCM via enterprise policy where federated sign-in is not required, using the FedCmEnabled policy set to false
Restrict browsing to trusted sites through enterprise URL allowlists until patching completes
Educate users to avoid interacting with sign-in prompts on unfamiliar sites

bash

# Example: disable FedCM via Chrome enterprise policy on Linux
cat <<'EOF' | sudo tee /etc/opt/chrome/policies/managed/fedcm_disable.json
{
  "FedCmEnabled": false
}
EOF

# On Windows, set the equivalent registry value:
# HKLM\Software\Policies\Google\Chrome\FedCmEnabled = 0 (DWORD)