External risk intelligence

IBM Langflow OSS Command Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-104339

IBM Langflow is a visual framework for building LLM applications. Such tools are commonly deployed as web-based interfaces or API services intended for user interaction, frequently making them reachable over the network or via public-facing endpoints in development and production environments.

Code 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 critical vulnerability has been identified in IBM Langflow OSS, a tool used for building AI applications. This flaw could permit unauthorized attackers to execute arbitrary code on affected systems, posing a significant risk due to the potential for system compromise and data exposure. The main concern is confirming if our environment utilizes this specific technology.

Vulnerability allows code execution over the network.
Critical flaw impacts AI application development tools.
Confirm relevance and exposure within our environment.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted commands over the network to a vulnerable instance of IBM Langflow. Because the system improperly handles certain special characters within these commands, it can be tricked into executing arbitrary operating system commands. This could allow an attacker to take control of the affected system.

No authentication or user interaction is required.
Attacker sends specially crafted OS commands.
Allows arbitrary code execution and system compromise.

Live Threat

Current exploitation, exposure, and threat context

IBM Langflow OSS, when deployed and accessible, could allow a remote attacker to execute arbitrary code. This is due to how the system handles special elements within operating system commands.

Arbitrary code execution on the server.
Exploiting a flaw in OS command processing.
System compromise and data theft.

Operational Fix

Recommended remediation, mitigation, and detection steps

IBM Langflow OSS, a framework for building LLM applications, is likely deployed as a web-based interface or API service, making it accessible over the network. This means ownership could reside with application owners, platform teams managing the deployment environment, or security teams responsible for network exposure. The initial practical step is to identify all instances of IBM Langflow, confirm their network reachability and business criticality, and then determine the accountable owner to plan remediation based on risk.

Application or platform teams should own.
Verify network exposure and criticality.
Plan risk-based remediation actions.

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 IBM Langflow OSS?

IBM Langflow OSS is a visual framework designed to help developers create and manage applications powered by Large Language Models (LLMs). It typically functions as a web-based interface or an API service, allowing users to build complex workflows and AI-driven processes through a graphical environment.

What does CVE-2026-104339 mean?

This CVE describes a weakness known as improper neutralization of special elements used in an OS command, classified as CWE-94. In plain terms, the software fails to properly filter input, allowing an attacker to inject and execute their own operating system commands directly on the server hosting the application.

How can an attacker trigger this vulnerability?

An attacker exploits this by sending specially crafted commands over the network to a running instance of the application. The system processes these inputs and mistakenly treats them as valid system instructions. Note that this bug does not require any authentication or user interaction to occur; it is triggered solely by the receipt of malicious network traffic.

Is my instance of IBM Langflow at risk?

According to Halo Surface Signal, this software is frequently deployed as a public-facing endpoint, which increases the likelihood that your instance is reachable over the network. If your Langflow deployment is accessible from the internet, it is at higher risk of being targeted by remote actors compared to an instance restricted to an isolated internal network.

What should I do if I run this software?

Your first step is to locate all instances of IBM Langflow within your environment to understand your footprint. Once identified, verify whether each instance is accessible over the network and assess its business criticality. Finally, coordinate with the application or platform owners responsible for those specific servers to prepare for necessary risk-based remediation.

References

www.ibm.com/support/pages/node/7293015

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.