CVE-2026-5273: Google Chrome Use After Free Vulnerability

CVE-2026-5273 Overview

CVE-2026-5273 is a Use After Free vulnerability in the CSS component of Google Chrome prior to version 146.0.7680.178. This memory corruption flaw allows a remote attacker to potentially execute arbitrary code inside a sandbox via a crafted HTML page. The vulnerability was classified with High severity by the Chromium security team.

Critical Impact

Remote attackers can exploit this vulnerability by convincing users to visit a malicious webpage containing specially crafted CSS, potentially leading to arbitrary code execution within Chrome's sandbox environment.

Affected Products

• Google Chrome versions prior to 146.0.7680.178
• Affects Chrome on Microsoft Windows
• Affects Chrome on Apple macOS
• Affects Chrome on Linux

Discovery Timeline

• 2026-04-01 - CVE-2026-5273 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2026-5273

Vulnerability Analysis

This Use After Free (CWE-416) vulnerability exists in Google Chrome's CSS rendering engine. Use After Free vulnerabilities occur when a program continues to use memory after it has been freed, which can lead to corruption of valid data or execution of arbitrary code. In this case, the vulnerability is triggered during CSS processing when the browser improperly handles memory allocation during style computation or layout operations.

The attack requires user interaction—specifically, a victim must be lured to a malicious website hosting the crafted HTML page. While successful exploitation allows code execution, it occurs within Chrome's sandbox, providing an additional layer of defense that limits the immediate impact on the underlying system.

Root Cause

The root cause of this vulnerability lies in improper memory lifecycle management within Chrome's CSS processing code. When certain CSS constructs are parsed or rendered, the browser may free a memory object but retain a dangling pointer to that freed memory. Subsequent operations that reference this pointer can lead to use of the freed memory region, potentially allowing an attacker to control program execution or corrupt data.

Attack Vector

The attack vector for CVE-2026-5273 is network-based, requiring no privileges on the target system but requiring user interaction. An attacker would need to:

1. Create a malicious HTML page containing specially crafted CSS that triggers the Use After Free condition
2. Convince a target user to visit the malicious page (via phishing, malvertising, or compromised websites)
3. When the victim's browser processes the malicious CSS, the memory corruption occurs
4. The attacker can potentially achieve code execution within the browser's sandbox

The vulnerability is exploitable remotely without authentication, though successful exploitation is constrained by Chrome's sandbox architecture.

Detection Methods for CVE-2026-5273

Indicators of Compromise

• Unexpected Chrome crashes or memory access violations during web browsing
• Browser process crashes specifically related to CSS rendering or style computation
• Detection of known malicious URLs or domains hosting exploit pages

Detection Strategies

• Monitor for Chrome crash reports indicating memory corruption in CSS-related components
• Deploy network-based detection for known exploit patterns in HTML/CSS content
• Utilize endpoint detection solutions capable of identifying Use After Free exploitation attempts
• Review browser telemetry for anomalous CSS processing behavior

Monitoring Recommendations

• Enable Chrome's crash reporting to capture diagnostic data for potential exploitation attempts
• Monitor network traffic for suspicious HTML pages with complex or obfuscated CSS
• Deploy SentinelOne Singularity endpoint protection to detect memory corruption exploitation in real-time
• Implement web filtering to block access to known malicious domains

How to Mitigate CVE-2026-5273

Immediate Actions Required

• Update Google Chrome to version 146.0.7680.178 or later immediately
• Enable automatic updates in Chrome to receive security patches promptly
• 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 146.0.7680.178. The fix is included in the stable channel release announced on the Google Chrome Releases Blog. Organizations should prioritize deployment of this update across all managed Chrome installations. Additional technical details may be available in the Chromium Issue Tracker.

Workarounds

• Restrict browsing to trusted websites until the patch can be applied
• Use browser isolation technology to contain potential exploitation
• Consider temporarily using an alternative browser for high-risk browsing activities
• Implement content security policies that restrict CSS sources where feasible

# Verify Chrome version to confirm patch status
# On Windows (PowerShell):
(Get-Item "C:\Program Files\Google\Chrome\Application\chrome.exe").VersionInfo.FileVersion

# On macOS:
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version

# On Linux:
google-chrome --version
# Ensure version is 146.0.7680.178 or higher