CVE-2026-78948: Google Chrome Buffer Overflow Vulnerability

CVE-2026-78948 Overview

CVE-2026-78948 is a heap-based buffer overflow [CWE-122] in the WebGL component of Google Chrome. Versions prior to 152.0.7977.65 are affected. A remote attacker can execute arbitrary code outside the Chrome sandbox by convincing a user to load a crafted HTML page. The flaw impacts confidentiality, integrity, and availability, and results in a scope change because sandbox escape allows the attacker to reach the underlying operating system context.

Critical Impact
Remote attackers can achieve arbitrary code execution outside the Chrome sandbox through a crafted web page, bypassing the browser's primary containment boundary.

Affected Products

Google Chrome (Desktop) versions prior to 152.0.7977.65
Chromium-based browsers sharing the same WebGL code path
All supported desktop platforms (Windows, macOS, Linux)

Discovery Timeline

2026-08-25 - CVE-2026-78948 published to NVD
2026-08-27 - Last updated in NVD database

Technical Details for CVE-2026-78948

Vulnerability Analysis

The vulnerability is a heap buffer overflow in Chrome's WebGL implementation, the browser subsystem that provides GPU-accelerated 3D graphics to JavaScript. WebGL processes buffers, textures, and shader inputs supplied by untrusted web content, which places it on Chrome's most exposed attack surface.

Exploitation requires only that a victim visits an attacker-controlled or compromised page. The Chromium project rated the issue High severity internally. Because the flaw yields code execution outside the sandbox, an attacker escapes the renderer process and executes native code with the privileges of the browser user.

Root Cause

The root cause is improper bounds handling on a heap-allocated buffer within the WebGL subsystem. When crafted graphics data is submitted through the WebGL API, the code writes past the end of the allocation. Overwriting adjacent heap metadata or object pointers gives an attacker control of program state, ultimately leading to arbitrary code execution.

Attack Vector

The attack vector is network-based and requires user interaction limited to loading a malicious HTML page. No authentication is required. Attackers typically deliver the payload through phishing links, malvertising, watering-hole compromises, or embedded iframes on trusted sites. The scope change reflects the sandbox escape: code that begins execution inside the constrained renderer breaks out to the host operating system context.

No public proof-of-concept is available at the time of publication, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Technical details are tracked in Chromium Issue #529991907.

Detection Methods for CVE-2026-78948

Indicators of Compromise

Chrome renderer or GPU process crashes with heap corruption signatures generated shortly after loading a WebGL-heavy page
Child processes spawned by chrome.exe that are inconsistent with normal browser behavior, such as shells, script interpreters, or LOLBins
Outbound connections from Chrome to newly registered or low-reputation domains hosting WebGL content
Unexpected file writes to user profile directories or startup locations immediately following browser activity

Detection Strategies

Inventory Chrome installations across the fleet and flag any host running a version below 152.0.7977.65
Alert on anomalous process lineage where Chrome spawns non-browser child processes, a common post-exploitation pattern for sandbox escapes
Correlate browser crash telemetry with subsequent process creation, network, and file system events to surface exploitation attempts

Monitoring Recommendations

Ingest Chrome crash and stability telemetry into a centralized data lake for retrospective hunting
Monitor DNS and proxy logs for user visits to unfamiliar domains preceding renderer crashes
Track EDR-reported memory protection violations originating from browser processes

How to Mitigate CVE-2026-78948

Immediate Actions Required

Update Google Chrome to version 152.0.7977.65 or later on all Windows, macOS, and Linux endpoints
Force a browser restart after update deployment to ensure the patched binaries are loaded
Audit and update Chromium-based browsers (Edge, Brave, Opera, Vivaldi) once vendors ship patches incorporating the upstream fix
Restrict user browsing to trusted sites through web filtering while patch rollout completes

Patch Information

Google released the fix in the Stable channel update announced on the Chrome Releases blog. Upgrading to Chrome 152.0.7977.65 or later removes the vulnerable WebGL code path. Enterprises using managed deployment should confirm that automatic updates are enabled or push the new build through their software management platform.

Workarounds

Disable WebGL through enterprise policy by setting WebGLEnabled to false via Chrome Group Policy or the policies.json file on unmanaged Linux hosts
Deploy site isolation and strict content security policies to reduce the impact of a compromised renderer
Use application allowlisting to prevent Chrome from launching unexpected child processes

bash

# Chrome enterprise policy to disable WebGL as a temporary workaround
# Windows registry path:
# HKLM\Software\Policies\Google\Chrome\WebGLEnabled = 0

# Linux policies.json example (/etc/opt/chrome/policies/managed/webgl.json)
{
  "WebGLEnabled": false,
  "HardwareAccelerationModeEnabled": false
}