External risk intelligence

Google Chrome Autofill Sandbox Escape via Malicious Network Traffic

CVE advisorySeverity: CRITICAL (CVSS 9.6)

CVE-2026-11207

This vulnerability affects the Autofill feature within a client-side web browser. While it requires processing network traffic, the attack surface is inherent to client-side software execution on a user's device rather than a server-side, public-facing, or internet-accessible service.

Google Chrome

before 149.0.7827.53

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

An insufficient validation issue in Google Chrome's Autofill feature could allow remote attackers to escape the browser's security sandbox through malicious network traffic. This vulnerability poses a potential risk if exploited, as it could lead to broader system compromise.

Input validation flaw in browser Autofill.
Could allow attackers to bypass security.
Confirm relevance and exposure of affected systems.

Attack Path

How an attacker could exploit the issue

An attacker could initiate this attack by sending specially crafted network traffic to a user's browser. This traffic would exploit a flaw in the browser's autofill feature, which fails to properly validate the input it receives. If successful, this could allow the attacker to break out of the browser's security sandbox.

Requires network access.
Triggers via autofill input.
Enables sandbox escape.

Live Threat

Current exploitation, exposure, and threat context

A sandbox escape vulnerability in Chrome's Autofill feature could allow a remote attacker to execute code outside the browser's isolated environment when a user interacts with specially crafted network traffic. This could affect system data and user data on the affected device.

System data and user data on the device.
Via malicious network traffic and user interaction.
Potential for broader system compromise.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability affects Google Chrome's Autofill feature and requires a user to interact with malicious network traffic, potentially leading to a sandbox escape. Ownership likely falls to teams managing end-user workstations and the browser deployment, such as endpoint management or security operations. The immediate first step is to identify all instances of the affected browser version, assess user exposure, and plan for an update, coordinating with user communications and support teams.

End-user compute and security teams.
Verify affected Chrome browser instances.
Plan and deploy browser updates.

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 Google Chrome and its Autofill feature?

Google Chrome is a widely used web browser that renders internet content on devices running Windows, macOS, or Linux. The Autofill feature is a built-in convenience tool that automatically saves and inserts data—such as addresses, names, and payment details—into web forms to save users time. It constantly monitors and processes incoming information from websites to identify fields where this stored data can be applied.

What does CVE-2026-11207 mean by sandbox escape?

This vulnerability is classified as Improper Input Validation (CWE-20). In simple terms, the browser's Autofill component fails to thoroughly check the data it receives from a website. Because the browser runs in a 'sandbox'—a restricted environment designed to keep malicious code from affecting your computer—this validation failure acts as a flaw that could allow an attacker to break through that security wall and access the underlying operating system.

How is this Chrome vulnerability triggered?

An attacker triggers this by sending specially crafted network traffic to your browser, which the Autofill feature then incorrectly processes. Crucially, simply browsing the internet does not automatically trigger the bug; the process relies on the browser interacting with malicious traffic that exploits the validation flaw. The vulnerability does not activate if the Autofill feature is not actively parsing or validating the specific malformed input provided by the attacker.

Why does Halo Surface Signal rate this as unlikely to impact servers?

Halo Surface Signal labels this as 'Very unlikely' because the risk is tied to client-side browser software on a user's device, not a server-side service. While the attack uses network traffic, it targets the end-user's local environment rather than an internet-facing server infrastructure. Therefore, the threat is primarily relevant to managed workstations or personal devices where users are actively browsing the web, rather than to internal network servers.

Do I need to update my software to fix this?

Yes. The most effective step is to ensure your Chrome browser is updated to version 149.0.7827.53 or higher, as this update contains the necessary validation improvements. Since this involves browser software, you should coordinate with the teams that manage your organization's workstation deployments to confirm that all systems are patched. Focus on identifying outdated browser versions across your fleet and prioritizing the deployment of the stable update.

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.