CVE-2026-6312: Google Chrome Information Disclosure Flaw

CVE-2026-6312 Overview

CVE-2026-6312 is an insufficient policy enforcement vulnerability affecting the Passwords component in Google Chrome prior to version 147.0.7727.101. This security flaw allows a remote attacker who has already compromised the renderer process to leak cross-origin data through a crafted HTML page. The vulnerability represents a policy enforcement weakness that could enable attackers to bypass browser security boundaries designed to protect user data.

Critical Impact

Attackers with renderer process access can exfiltrate sensitive cross-origin data, potentially exposing user credentials and other protected information stored in the Chrome password manager.

Affected Products

• Google Chrome versions prior to 147.0.7727.101

Discovery Timeline

• 2026-04-15 - CVE CVE-2026-6312 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-6312

Vulnerability Analysis

This vulnerability stems from insufficient policy enforcement within Chrome's Passwords component. The flaw enables an attacker who has already achieved renderer process compromise to circumvent cross-origin protections. In a normal browser security model, strict isolation policies prevent data from one origin (website) from being accessed by another origin. However, this vulnerability weakens those enforcement mechanisms specifically around password-related data.

The attack requires the adversary to first compromise the renderer process through a separate vulnerability or attack chain. Once renderer access is achieved, the attacker can then craft malicious HTML content designed to exploit the policy enforcement gap and extract cross-origin data that should otherwise be protected by the same-origin policy.

Root Cause

The root cause lies in inadequate policy enforcement logic within the Passwords component of Google Chrome. The component fails to properly validate or enforce cross-origin access restrictions when the renderer process has been compromised, creating a pathway for data leakage that bypasses normal browser security boundaries.

Attack Vector

The attack requires network access and user interaction - specifically, a victim must navigate to a malicious page controlled by the attacker. The attack is considered high complexity because it first requires the attacker to compromise the renderer process before this vulnerability can be exploited.

The exploitation scenario involves:

1. Attacker first compromises the Chrome renderer process through a separate vulnerability
2. Attacker hosts or injects a specially crafted HTML page
3. Victim visits the malicious page while having saved passwords in Chrome
4. The crafted HTML exploits the policy enforcement weakness to leak cross-origin data

For technical details on the vulnerability mechanism, see the Chromium Issue Report #498269651 and the Google Chrome stable channel update announcement.

Detection Methods for CVE-2026-6312

Indicators of Compromise

• Anomalous cross-origin requests originating from the browser's password component
• Unusual renderer process behavior or memory access patterns
• Unexpected data exfiltration attempts from browser processes to external destinations

Detection Strategies

• Monitor browser process behavior for signs of renderer compromise, which is a prerequisite for exploiting this vulnerability
• Implement network monitoring to detect unusual cross-origin data transfers
• Deploy endpoint detection solutions capable of identifying browser-based data exfiltration attempts

Monitoring Recommendations

• Enable Chrome's enhanced protection mode to help detect potentially dangerous sites
• Monitor browser extension activity for suspicious behavior that could indicate renderer compromise
• Review browser update deployment status across enterprise environments to identify unpatched systems

How to Mitigate CVE-2026-6312

Immediate Actions Required

• Update Google Chrome to version 147.0.7727.101 or later immediately
• Enable automatic Chrome updates to ensure timely security patches
• Review browser policy configurations to ensure password autofill is disabled on untrusted sites where appropriate

Patch Information

Google has addressed this vulnerability in Chrome version 147.0.7727.101. The fix strengthens policy enforcement in the Passwords component to prevent cross-origin data leakage even when the renderer process has been compromised. Organizations should prioritize updating Chrome installations across their environment.

For detailed information about the patch, refer to the Google Chrome stable channel update announcement.

Workarounds

• Consider using a separate browser profile without saved passwords for browsing untrusted sites
• Enable site isolation features to strengthen renderer process boundaries
• For enterprise environments, consider deploying browser policies that restrict password autofill functionality until patching is complete

# Verify Chrome version on Linux/macOS
google-chrome --version

# Enterprise policy to disable password manager (Windows Registry)
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome
# PasswordManagerEnabled = 0