CVE-2025-10890: Google Chrome Information Disclosure Flaw

CVE-2025-10890 Overview

CVE-2025-10890 is a side-channel information leakage vulnerability in the V8 JavaScript engine used by Google Chrome. This vulnerability allows a remote attacker to leak cross-origin data via a crafted HTML page. V8 is the core JavaScript and WebAssembly engine that powers Chrome's execution of web content, making this a significant security concern for all Chrome users. The flaw enables attackers to bypass the browser's same-origin policy protections through timing-based side-channel techniques, potentially exposing sensitive data from other websites the user is authenticated to.

Critical Impact

Remote attackers can exploit this side-channel vulnerability to leak cross-origin data, potentially compromising user credentials, session tokens, and sensitive information from other websites without requiring any user interaction beyond visiting a malicious page.

Affected Products

• Google Chrome prior to version 140.0.7339.207
• Google Chrome on Apple macOS
• Google Chrome on Linux
• Google Chrome on Microsoft Windows

Discovery Timeline

• 2025-09-24 - CVE-2025-10890 published to NVD
• 2025-09-25 - Last updated in NVD database

Technical Details for CVE-2025-10890

Vulnerability Analysis

This vulnerability is classified under CWE-1300 (Improper Protection of Physical Side Channels) and CWE-203 (Observable Discrepancy). The flaw exists within Chrome's V8 JavaScript engine, which is responsible for executing JavaScript code in web pages. Side-channel attacks exploit observable behaviors such as timing differences, cache states, or resource consumption patterns to infer information that should be protected by security boundaries.

In this case, the vulnerability allows an attacker to craft a malicious HTML page that can measure timing differences or other observable behaviors in V8's execution to leak data from cross-origin contexts. This effectively bypasses the same-origin policy, a fundamental browser security mechanism designed to prevent web pages from accessing data belonging to other origins.

The vulnerability requires no privileges and no user interaction beyond visiting the attacker-controlled page, making it particularly dangerous for targeted attacks.

Root Cause

The root cause stems from improper isolation of observable side-channel signals within V8's execution environment. When processing JavaScript operations involving cross-origin resources, the engine inadvertently allows timing or other measurable differences that correlate with the protected data. This creates an observable discrepancy that sophisticated attackers can exploit to reconstruct sensitive information bit by bit.

Attack Vector

The attack is network-based and requires the victim to visit a malicious webpage controlled by the attacker. The crafted HTML page contains JavaScript code designed to:

1. Trigger V8 operations that interact with cross-origin data indirectly
2. Measure timing differences or other observable behaviors during these operations
3. Statistically analyze the measurements to infer the protected data values
4. Exfiltrate the recovered information to the attacker's server

The vulnerability exploits observable discrepancies in V8's execution, requiring precise timing measurements and statistical analysis to successfully leak data. Modern CPUs with high-resolution timers make such attacks more practical.

Detection Methods for CVE-2025-10890

Indicators of Compromise

• Unusual JavaScript execution patterns involving high-precision timing measurements such as performance.now() or SharedArrayBuffer
• Web pages attempting to access cross-origin resources in suspicious patterns
• Anomalous network traffic to unknown domains following visits to suspicious websites
• Browser performance degradation due to intensive timing measurement loops

Detection Strategies

• Monitor for JavaScript code patterns commonly used in side-channel attacks, including timing measurement loops and statistical analysis functions
• Implement Content Security Policy (CSP) headers to restrict the execution of untrusted scripts
• Use browser extensions or enterprise policies to block access to known malicious domains
• Deploy endpoint detection solutions capable of identifying browser-based exploitation attempts

Monitoring Recommendations

• Enable enhanced browser telemetry to detect anomalous JavaScript execution patterns
• Monitor network traffic for data exfiltration attempts following visits to suspicious web pages
• Review browser extension activity for potential exploitation vectors
• Implement web proxy filtering to block access to newly registered or suspicious domains

How to Mitigate CVE-2025-10890

Immediate Actions Required

• Update Google Chrome to version 140.0.7339.207 or later immediately across all systems
• Enable automatic updates for Chrome to ensure timely patching of future vulnerabilities
• Educate users about the risks of visiting untrusted websites
• Consider deploying browser isolation solutions for high-risk users

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 140.0.7339.207. The patch is available for Windows, macOS, and Linux platforms. Organizations should prioritize deployment of this update, particularly for systems handling sensitive data or used by high-value targets.

For detailed patch information, refer to the Google Chrome Stable Channel Update announcement. Additional technical details may be available in the Chromium Issue Tracker.

Workarounds

• Restrict access to untrusted websites through web filtering or proxy solutions until the patch can be applied
• Consider temporarily using an alternative browser for sensitive operations if Chrome cannot be immediately updated
• Disable JavaScript execution for untrusted sites using browser settings or extensions like NoScript
• Implement network-level controls to prevent data exfiltration from potentially compromised browsers

# Chrome Enterprise Policy Configuration (Windows Registry)
# Enforce minimum Chrome version to ensure patched version is deployed
reg add "HKLM\SOFTWARE\Policies\Google\Chrome" /v "MinimumVersionRequired" /t REG_SZ /d "140.0.7339.207" /f

# Enable automatic updates
reg add "HKLM\SOFTWARE\Policies\Google\Update" /v "AutoUpdateCheckPeriodMinutes" /t REG_DWORD /d 60 /f