External risk intelligence

Google Chrome WebGL Use After Free Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.6)

CVE-2026-121246

This vulnerability affects WebGL in a web browser, which is a client-side application. While it can be triggered by a user visiting a malicious website, the vulnerability itself resides in the client software on the endpoint, not in an internet-facing server, appliance, or service that would be exposed to direct, unsolicited internet-based attacks.

Use After Free

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Google Chrome on Android, related to how WebGL handles memory. This flaw could allow a remote attacker to execute malicious code on a user's device by luring them to a specially crafted webpage. While the potential for code execution is high, the primary concern for leadership is confirming if this specific browser component is relevant to your organization's technology footprint and user base.

Browser memory flaw allows code execution.
Critical flaw; verify relevance to our systems.
Confirm exposure, then prioritize remediation.

Attack Path

How an attacker could exploit the issue

An attacker could trick a user into visiting a malicious webpage, which then interacts with the browser's WebGL component. This interaction could lead to a use-after-free condition within the browser, potentially allowing the attacker to execute code on the user's device.

Remote attackers can reach the vulnerability.
A crafted HTML page triggers the vulnerability.
Arbitrary code execution outside the sandbox.

Live Threat

Current exploitation, exposure, and threat context

A use-after-free vulnerability in Chrome's WebGL component on Android could allow an attacker to execute arbitrary code outside the browser's sandbox. This could occur when a user visits a specially crafted HTML page.

Arbitrary code execution.
Remote attacker via malicious web page.
Compromised user device.

Operational Fix

Recommended remediation, mitigation, and detection steps

Understanding who should act on this vulnerability requires identifying the teams responsible for managing user endpoints and browser security. The first practical step is to determine the presence of affected Chrome versions on user devices, assess the potential exposure, and confirm ownership of those endpoints before planning remediation.

Own by endpoint management or security teams.
Verify Chrome version and reachability.
Plan targeted updates or user guidance.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the WebGL component in Google Chrome?

WebGL is a JavaScript API integrated into Google Chrome that allows the browser to render high-performance 2D and 3D graphics directly within a webpage. By leveraging the device's graphics processing unit (GPU), it enables complex visual experiences and interactive content without requiring external plugins.

What does a use-after-free weakness mean in CVE-2026-121246?

A use-after-free is a memory management error that occurs when software continues to use a pointer to a memory location after that memory has been cleared or freed. In this vulnerability, an attacker can manipulate this flaw to replace the freed memory with malicious instructions, potentially gaining control over the browser's execution flow.

How is the CVE-2026-121246 vulnerability triggered?

The vulnerability is triggered when a user navigates to a specifically crafted HTML page designed to exploit the memory error in WebGL. It is not triggered by standard web browsing or by visiting legitimate, secure websites; the attacker must successfully lure the user to malicious content that interacts with the vulnerable browser code.

Is this vulnerability a risk for my servers according to Halo Surface Signal?

According to Halo Surface Signal, this vulnerability is classified as 'Very unlikely' to impact server infrastructure. Because it exists in a client-side web browser on Android devices rather than in internet-facing services or server applications, it does not represent a direct, unsolicited attack vector against your internal server network.

What should I do if I am running Google Chrome on Android?

Your primary step is to identify all Android devices in your organization using the affected Chrome version. Once identified, coordinate with your endpoint management team to prioritize the application of security updates provided by Google to patch the browser, as these updates contain the necessary code corrections to prevent the memory handling error.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.