Overview
CVE-2025-9479 is a security vulnerability affecting Google Chrome’s V8 JavaScript engine. This out-of-bounds read flaw, present in versions prior to 133.0.6943.141, could allow a remote attacker to potentially exploit heap corruption through a specially crafted HTML page. The vulnerability is classified as a Medium severity issue by Chromium security.
Technical Details
The vulnerability stems from an out-of-bounds read within the V8 JavaScript engine. An attacker could craft a malicious HTML page designed to trigger the vulnerability. When the user opens the page in a vulnerable version of Chrome, the V8 engine might attempt to read data beyond the allocated memory boundaries, leading to potential heap corruption. This heap corruption could then be exploited to gain control of the browser process.
The exact mechanism involves manipulating JavaScript code in the HTML page to trigger an improper memory access within V8. Details of the specific code paths and data structures involved are often withheld to prevent further exploitation before users have a chance to update.
CVSS Analysis
As of the publication date of this article (2025-11-14), the CVSS score for CVE-2025-9479 is not available (N/A). However, Chromium classifies this as a Medium severity issue. A CVSS score will likely be assigned after further analysis, taking into account factors such as attack complexity, privileges required, user interaction, and scope.
While the score is N/A currently, the potential for heap corruption elevates the risk associated with this vulnerability.
Possible Impact
Successful exploitation of CVE-2025-9479 could have significant consequences:
- Information Disclosure: An attacker might be able to read sensitive data from the browser’s memory.
- Denial of Service (DoS): The vulnerability could cause the browser to crash.
- Remote Code Execution (RCE): While less likely, heap corruption could potentially be leveraged to execute arbitrary code on the user’s system, although this is complex and requires further exploitation techniques.
Mitigation or Patch Steps
The most effective mitigation is to update Google Chrome to version 133.0.6943.141 or later. Google has already released a patch that addresses this vulnerability.
- Check your Chrome version: Go to
chrome://settings/helpin your Chrome browser to check your current version. - Update Chrome: If your version is older than 133.0.6943.141, Chrome will automatically download and install the update. You may need to restart Chrome to complete the update process.
- Enable Automatic Updates: Ensure that automatic updates are enabled to receive security patches promptly.
