External risk intelligence

Firefox WebGPU Sandbox Escape Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-13026

This vulnerability affects the WebGPU component within a client-side web browser. Browser components are inherently local-side software used by end-users. While web browsers interact with the internet, the component itself is not a network-facing service, gateway, or externally accessible infrastructure, making it very unlikely to be exposed as a public-facing attack surface in the context of network deployment.

Mozilla Firefox

before 145.0

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 the Graphics: WebGPU component of Firefox, allowing for sandbox escape. This means an attacker could potentially break out of the browser's restricted environment. While the main concern is confirming relevance and exposure, this type of issue could, in certain circumstances, lead to broader system compromise if exploited.

Web browser component allows escaping restrictions.
Executive takeaway: Confirm relevance and assess exposure.
Understand the risk to browser users.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by directing a user to a specially crafted web page. This page would trigger a flaw in the browser's graphics component, potentially allowing the attacker to break out of the browser's secure sandbox.

No authentication or user interaction needed.
Malicious webpage interaction.
Sandbox escape leading to system compromise.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in the Graphics: WebGPU component could allow an attacker to escape the browser's sandbox. This could happen when a user visits a malicious website, potentially leading to unauthorized access to the user's system.

User system data.
Malicious website interaction.
Sandbox escape and system compromise.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Graphics: WebGPU component in Firefox is affected by a sandbox escape vulnerability. Responsibility for addressing this likely falls to teams managing end-user applications, such as desktop support or IT operations, in coordination with browser administrators or vendor management if a managed solution is in place. The immediate first step is to confirm the presence of the affected browser versions, assess business criticality, and then plan remediation, potentially involving phased rollouts or vendor engagement for updates.

Ownership by desktop support or IT operations.
Verify affected browser versions exist.
Plan phased update rollout.

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 Firefox Graphics: WebGPU component?

WebGPU is a technology that allows browsers like Firefox to access your computer's graphics hardware directly. This enables high-performance tasks, such as rendering complex 3D graphics or running intensive calculations for web applications, directly within the browser environment.

What does sandbox escape mean for CVE-2025-13026?

This vulnerability involves a weakness classified as CWE-703, which relates to improper check or handling of exceptional conditions. In this case, the browser's security sandbox—a restricted environment designed to contain web content—fails to correctly manage boundary conditions, allowing code to break out of its container and interact directly with your system.

How does an attacker trigger this vulnerability?

An attacker triggers this by directing a user to a specifically designed webpage that exploits the graphics component flaw. It is important to note that simply having the browser installed does not trigger the bug; the malicious code must be executed by visiting the compromised or attacker-controlled site.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal notes that this vulnerability affects a client-side component within a web browser, not a public-facing network service or infrastructure. Because it is local-side software, it is considered very unlikely to be exposed as an external network-facing attack surface.

Do I need to update my browser to address CVE-2025-13026?

Yes. The first step is to check if you are running a version of Firefox or Thunderbird older than 145. If you are, you should prioritize updating to version 145 or later, as this release contains the necessary security fixes to resolve the sandbox boundary flaw.

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.