External risk intelligence

h-ui Command Injection Vulnerability Affecting v0.0.25 and Below

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-107202

The vulnerability resides in an administrative API. Administrative interfaces and APIs for network configuration tools are commonly deployed as internet-facing management services or gateways, making them reachable from external networks in typical configurations.

Command Injection

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A command injection vulnerability has been identified in the h-ui administrative API. This flaw allows authenticated administrators to execute arbitrary operating system commands with root privileges by exploiting improper validation of the listen configuration field, potentially impacting system security and integrity.

Administrative API allows unauthorized command execution.
Matters due to root-level access and system compromise.
Confirm relevance and exposure to the administrative API.

Attack Path

How an attacker could exploit the issue

An attacker with administrative access can exploit this vulnerability by providing specially crafted input to the administrative API's listen configuration field. Because the application does not properly validate this input, it can be manipulated to include shell metacharacters. The application then uses this input to construct and execute system commands with root privileges, potentially leading to full system compromise.

Requires authenticated administrator access.
Triggered by providing shell metacharacters in the listen configuration.
Allows arbitrary command execution as root.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an attacker with administrator access to execute arbitrary commands with root privileges on the affected system. This occurs when the administrative API improperly validates the `listen` configuration field, enabling the injection of shell metacharacters that are then used to construct and execute network filtering rules.

System commands could be executed.
Via crafted API configuration input.
Root-level system compromise is possible.

Operational Fix

Recommended remediation, mitigation, and detection steps

The h-ui administrative API's command injection vulnerability requires immediate attention from teams responsible for managing network infrastructure and security. Given that the vulnerability allows for remote code execution as root and affects an administrative API, infrastructure and platform teams must prioritize identifying all instances of h-ui, assessing their exposure, and confirming business criticality. Coordination with the vendor will be necessary for a complete remediation plan.

Infrastructure and platform teams own remediation.
Verify h-ui presence and external reachability.
Plan remediation based on risk assessment.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is h-ui software?

h-ui is a tool used for managing network configurations. It provides an administrative API that allows users to define how the system handles network traffic, such as managing listen configurations for network filtering rules.

What does CWE-77 mean for CVE-2026-107202?

CWE-77, or Command Injection, means the software improperly processes user input by passing it directly to a system shell. In this case, the application fails to sanitize the listen configuration field, allowing a user to insert special shell characters that the system then executes as if they were legitimate commands.

How is this command injection triggered?

The issue is triggered when an authenticated administrator inputs shell metacharacters into the listen configuration field. The vulnerability is not triggered by standard, valid port or configuration data; it specifically requires the injection of malicious command syntax that the underlying system shell then interprets.

Why should I care about this vulnerability?

Halo Surface Signal notes that administrative APIs for network tools are often deployed as internet-facing gateways. Because this flaw grants root-level command execution, an attacker reaching this interface from an external network could gain full control over the host system.

Do I need to update my h-ui deployment?

You should first verify if you are running version v0.0.25 or older. If so, prioritize identifying these instances in your environment and assessing their network reachability. Coordinate with the vendor to determine the availability of patches or safer configuration alternatives to mitigate the risk of unauthorized root access.

References

github.com/jonssonyan/h-ui

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.