CVE-2026-4674: Google Chrome RCE Vulnerability

CVE-2026-4674 Overview

CVE-2026-4674 is an out-of-bounds read vulnerability in the CSS processing component of Google Chrome prior to version 146.0.7680.165. This memory safety flaw allows a remote attacker to perform out-of-bounds memory access by enticing a victim to visit a specially crafted HTML page. The vulnerability carries a Chromium security severity rating of High.

Critical Impact
Remote attackers can exploit this out-of-bounds read vulnerability to potentially access sensitive memory contents or cause application instability through crafted CSS in malicious web pages.

Affected Products

Google Chrome versions prior to 146.0.7680.165
Google Chrome on Microsoft Windows
Google Chrome on Apple macOS
Google Chrome on Linux

Discovery Timeline

2026-03-24 - CVE-2026-4674 published to NVD
2026-03-24 - Last updated in NVD database

Technical Details for CVE-2026-4674

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-bounds Read), a memory corruption issue that occurs when the CSS rendering engine reads data from a location outside the intended buffer boundaries. The flaw exists in Chrome's CSS parsing and processing code, where improper bounds checking allows memory reads beyond allocated buffer limits.

The vulnerability requires user interaction—specifically, a victim must navigate to or be redirected to a malicious webpage containing specially crafted CSS content. Once triggered, the out-of-bounds read can expose sensitive information stored in adjacent memory regions, potentially including cryptographic keys, session tokens, or other process memory contents.

Root Cause

The root cause of CVE-2026-4674 lies in insufficient boundary validation within Chrome's CSS processing engine. When parsing certain CSS constructs, the browser fails to properly validate array indices or buffer offsets before performing read operations. This allows attackers to craft CSS that causes the rendering engine to access memory outside the intended data structures.

The vulnerability is particularly concerning because CSS parsing occurs automatically when loading web content, making drive-by exploitation scenarios feasible without any user interaction beyond visiting a malicious page.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the attacker to serve malicious HTML/CSS content to the victim. Attack scenarios include:

Malicious Website: An attacker hosts a webpage containing specially crafted CSS that triggers the out-of-bounds read when rendered by the vulnerable Chrome browser.
Compromised Advertisements: Attackers inject malicious CSS through ad networks, reaching victims on legitimate websites.
Watering Hole Attacks: Compromising websites frequently visited by target users to serve the malicious CSS payload.

The vulnerability does not require authentication or special privileges, only that the victim's browser processes the attacker-controlled CSS content.

Detection Methods for CVE-2026-4674

Indicators of Compromise

Unexpected Chrome renderer process crashes or instability when visiting untrusted websites
Memory access violations or segmentation faults logged in system crash reports
Unusual network traffic to domains serving CSS-heavy content from unknown sources
Chrome crash dumps indicating memory corruption in CSS-related components

Detection Strategies

Monitor for Chrome crash reports that reference CSS rendering or style calculation components
Deploy browser security policies that restrict access to known malicious domains
Implement network-level inspection for suspicious HTML/CSS payloads in HTTP responses
Use endpoint detection and response (EDR) solutions to identify exploitation attempts through memory access pattern analysis

Monitoring Recommendations

Enable Chrome's enhanced protection mode to receive real-time warnings about dangerous sites
Monitor Chrome version deployments across enterprise environments to identify unpatched instances
Configure centralized crash reporting to detect potential exploitation attempts at scale
Review web proxy logs for connections to newly registered or suspicious domains

How to Mitigate CVE-2026-4674

Immediate Actions Required

Update Google Chrome to version 146.0.7680.165 or later immediately
Enable automatic browser updates across all enterprise endpoints
Consider using browser isolation technologies for high-risk users until patching is complete
Review and enforce content security policies that restrict external CSS loading where feasible

Patch Information

Google has released a security update addressing this vulnerability in Chrome version 146.0.7680.165. The patch includes improved bounds checking in the CSS processing engine to prevent out-of-bounds memory reads.

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

Organizations should prioritize this update given the network-based attack vector and the lack of authentication requirements for exploitation.

Workarounds

Enable Site Isolation in Chrome to limit the impact of potential memory disclosure across origins
Temporarily disable JavaScript on untrusted sites to reduce attack surface (though CSS itself remains processable)
Use browser-level ad blockers to reduce exposure to malicious third-party content
Consider deploying browser virtualization or containerization solutions for high-risk browsing activities

bash

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

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

# Verify Chrome version on macOS
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version

# Force Chrome update check (all platforms)
# Navigate to chrome://settings/help or Menu > Help > About Google Chrome