External risk intelligence

Chromecast Heap Overflow Allows Sandbox Escape

CVE advisorySeverity: CRITICAL (CVSS 9.6)

CVE-2026-13798

The vulnerability exists within the Chromecast renderer process in the Chrome browser and requires a victim to be lured into visiting a crafted HTML page to trigger the exploit. As a client-side component accessed through user interaction rather than a public-facing service, gateway, or internet-accessible appliance, it lacks the characteristics of an inherently public-facing attack surface.

Buffer Overflow

Google Chrome

before 150.0.7871.46

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 vulnerability has been identified in Google Chrome's Chromecast component that could allow an attacker to escape security restrictions by tricking a user into visiting a malicious webpage. This exploit requires an attacker to first compromise the browser's rendering process, indicating a sophisticated attack vector. The primary concern is to confirm if this specific technology is in use and if it is exposed to potential threats.

Remote code execution via malicious websites.
Confirms browser component security risks.
Assess exposure; focus on indirect user risk.

Attack Path

How an attacker could exploit the issue

An attacker could start by compromising a web browser's renderer process. From there, they could present a specially crafted HTML page to a user. Visiting this page could trigger a heap buffer overflow within Chromecast, potentially allowing the attacker to escape the browser's sandbox.

Renderer process compromise is required.
Triggered by visiting a malicious HTML page.
Risk of sandbox escape and further compromise.

Live Threat

Current exploitation, exposure, and threat context

A heap buffer overflow in Chromecast within Google Chrome could allow an attacker who has already compromised the renderer process to escape the sandbox by directing a user to a specially crafted HTML page. This could impact the integrity and confidentiality of system data and service behavior.

System data and service behavior at risk.
Through a crafted HTML page.
Potential sandbox escape.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability affects the Chromecast component within Google Chrome. The first practical step is to identify all instances of this component, confirm their reachability and business criticality, and then identify the accountable owner for remediation.

Identify affected Chrome instances.
Verify reachability and business criticality.
Plan remediation based on identified risk.

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 Chromecast component in Google Chrome?

Chromecast in Chrome is a built-in feature that enables media casting functionality, allowing users to stream content from their browser to external displays or devices. It functions as a sub-component within the browser's architecture, managing the communication and rendering tasks required to send media data over a network.

What does CVE-2026-13798 mean by heap buffer overflow?

This vulnerability, classified as CWE-122, occurs when the Chromecast component writes more data to a specific memory area, known as the heap, than it can hold. By overflowing this memory, an attacker might corrupt surrounding data, potentially gaining control over the program's execution to escape the browser's security sandbox.

How is this Chromecast vulnerability triggered?

To trigger the bug, an attacker must first successfully compromise the browser's renderer process. Once inside, they must trick a user into navigating to a specifically crafted HTML page. Simply having the Chromecast component installed or running does not trigger the vulnerability; it requires this specific sequence of process compromise followed by active user interaction with malicious content.

Is my browser at risk from this Chrome vulnerability?

According to Halo Surface Signal, this vulnerability is very unlikely to be exploited via standard remote network attacks because it is a client-side component. It requires a victim to be lured to a specific webpage rather than attacking a public-facing service or server. While the risk to internal systems is lower than an internet-facing appliance, the browser remains a primary target for user-targeted threats.

What should I do if I use Google Chrome?

The most effective way to address this issue is to ensure your browser is updated to version 150.0.7871.47 or later. Since this affects the Chromecast component integrated within the application, standard browser updates will deliver the necessary security patches. Prioritize identifying systems where Chrome is used in high-risk environments and verify that automatic update mechanisms are functioning correctly.

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.