CVE-2025-12431: Google Chrome Auth Bypass Vulnerability

CVE-2025-12431 Overview

CVE-2025-12431 is a navigation restriction bypass in the Extensions component of Google Chrome. The flaw affects Chrome versions prior to 142.0.7444.59 across Windows, macOS, and Linux. An attacker who convinces a user to install a malicious Chrome extension can bypass navigation restrictions through a crafted extension. Google classifies the Chromium security severity as High, while the assigned CVSS 3.1 base score is 6.5. The weakness maps to [CWE-288] (Authentication Bypass Using an Alternate Path or Channel).

Critical Impact
A crafted Chrome extension can bypass browser navigation restrictions, enabling redirection to attacker-controlled destinations and circumvention of security boundaries enforced by the extension platform.

Affected Products

Google Chrome prior to 142.0.7444.59 on Microsoft Windows
Google Chrome prior to 142.0.7444.59 on Apple macOS
Google Chrome prior to 142.0.7444.59 on Linux

Discovery Timeline

2025-11-10 - CVE-2025-12431 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-12431

Vulnerability Analysis

The vulnerability resides in Chrome's Extensions subsystem. Chrome enforces navigation restrictions that limit where extensions may direct the browser, including restricted schemes and privileged origins. An inappropriate implementation in the extension navigation handling logic allows a crafted extension to circumvent these controls. Exploitation requires the attacker to persuade a user to install a malicious extension. Once installed, the extension can trigger navigations that the browser's policy layer would otherwise block. The resulting impact includes limited confidentiality and integrity loss, consistent with unauthorized redirection and access to content boundaries the user did not intend to expose.

Root Cause

The underlying defect is an inappropriate implementation, categorized as [CWE-288]. Chrome's extension framework fails to consistently enforce navigation restrictions when specific extension-initiated flows are used. The policy check is either skipped or reachable via an alternate path, allowing the extension to reach destinations reserved for the browser or other privileged contexts.

Attack Vector

The attack vector is network-based but requires user action to install the malicious extension. After installation, no further user interaction is needed for the extension to invoke the bypassed navigation. Attackers typically deliver such extensions through social engineering, sideloading prompts, or compromised distribution channels. See the Chromium Issue Tracker Entry and the Google Chrome Update Announcement for vendor details. No public proof-of-concept code is available at this time.

Detection Methods for CVE-2025-12431

Indicators of Compromise

Unexpected Chrome extension installations outside the enterprise-approved list, particularly extensions requesting broad host permissions or tabs, webNavigation, or declarativeNetRequest permissions.
Browser telemetry showing extension-initiated navigations to chrome://, file://, or other restricted schemes.
Outbound connections from Chrome to unfamiliar domains immediately following extension installation events.

Detection Strategies

Inventory installed Chrome extensions across managed endpoints and compare against an allowlist maintained through Chrome Enterprise policy.
Monitor endpoint process telemetry for chrome.exe child processes and network connections correlated with new extension IDs.
Alert on Chrome versions below 142.0.7444.59 reported by asset management or EDR agents.

Monitoring Recommendations

Ingest Chrome Enterprise reporting into a centralized log platform to track extension install, update, and permission events.
Correlate extension install events with subsequent DNS and HTTP traffic to identify redirection abuse.
Track user-reported anomalies such as unexpected page redirects or credential prompts on unfamiliar origins.

How to Mitigate CVE-2025-12431

Immediate Actions Required

Update Google Chrome to version 142.0.7444.59 or later on all Windows, macOS, and Linux endpoints.
Audit currently installed extensions and remove any that are unapproved, unsigned, or requesting excessive permissions.
Enforce Chrome Enterprise policies ExtensionInstallBlocklist and ExtensionInstallAllowlist to restrict extension sources to vetted publishers.

Patch Information

Google addressed CVE-2025-12431 in the Stable Channel desktop update released on 2025-10-28. Fixed version: 142.0.7444.59 and later. Refer to the Google Chrome Update Announcement for release notes and the Chromium Issue Tracker Entry for the technical fix.

Workarounds

Block user-initiated extension installations through Chrome Enterprise policy until patching is complete.
Restrict extension installation to the Chrome Web Store using ExtensionInstallSources and disable developer mode on managed devices.
Provide user awareness guidance warning against installing extensions from untrusted sources or in response to unsolicited prompts.

bash

# Configuration example: Chrome Enterprise policy to restrict extensions (Windows registry)
reg add "HKLM\Software\Policies\Google\Chrome\ExtensionInstallBlocklist" /v 1 /t REG_SZ /d "*" /f
reg add "HKLM\Software\Policies\Google\Chrome\ExtensionInstallAllowlist" /v 1 /t REG_SZ /d "<approved-extension-id>" /f
reg add "HKLM\Software\Policies\Google\Chrome" /v DeveloperToolsAvailability /t REG_DWORD /d 2 /f