External risk intelligence

IBM Langflow Arbitrary Code Execution via Deserialization Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-104317

IBM Langflow is a workflow automation tool that utilizes a message broker. While such components are sometimes exposed to the public internet, they are frequently deployed within internal networks or protected by authentication mechanisms, and the CVE description does not specify that the vulnerable component is intended to be public-facing by design in standard deployments.

Deserialization

Langflow

1.0.0 to before 1.12.4

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This advisory addresses a critical vulnerability in IBM Langflow OSS, a tool used for workflow automation. The issue lies in its handling of untrusted data, which could allow an attacker to execute unauthorized code remotely. The main concern is confirming if our environment uses this technology and if it's exposed in a way that could be targeted.

Remote code execution via untrusted data.
Affects workflow automation technology.
Confirm relevance and potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by reaching the message broker component of IBM Langflow. Once access to the message broker is established, the attacker can send a crafted message that exploits the deserialization of untrusted data. This process could lead to the execution of arbitrary code on the affected system.

Network access to the message broker is required.
Sending a message triggers deserialization of untrusted data.
Risk of arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

A remote attacker who can reach the message broker might execute arbitrary code on the system by exploiting a deserialization vulnerability in IBM Langflow. This could impact system integrity and data confidentiality when the message broker is accessible.

System code execution.
Untrusted data deserialization.
Compromised system integrity.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Platform or Infrastructure teams are likely responsible for managing IBM Langflow OSS, especially if it's integrated into a larger workflow or automation system. The first practical step is to identify all instances of Langflow, confirm their network reachability and business criticality, then locate the specific system owner to plan remediation during a suitable maintenance window.

Platform/Infrastructure teams own the issue.
Verify network reachability and criticality.
Plan remediation with system owners.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is IBM Langflow OSS used for?

IBM Langflow OSS is a workflow automation tool designed to help users build and manage data processing pipelines. It frequently relies on a message broker component to handle communication and task distribution between different parts of the automation system.

What does CVE-2026-104317 mean by deserialization vulnerability?

This refers to a weakness classified as CWE-502. It occurs when an application takes data from an untrusted source and converts it back into an object without sufficient validation. In this case, an attacker can craft malicious data that the system interprets as valid instructions, leading to unauthorized code execution.

How is this vulnerability triggered?

An attacker must reach the message broker component to send a specifically crafted message. The flaw is not triggered by standard application use or authorized data flow; it requires an attacker to successfully reach and interact with that internal messaging component to force the unsafe deserialization process.

Do I need to worry if my Langflow instance is internal?

Halo Surface Signal notes that while the vulnerability is classified as external, Langflow deployments are frequently found within internal networks or protected by authentication. If your instance is not directly reachable from the public internet, the practical risk is significantly different than an internet-facing system.

How should I respond to this threat?

Begin by identifying all running instances of Langflow OSS within your environment. Once mapped, verify their network accessibility and business criticality. Coordinate with the platform or infrastructure teams to review the system configuration and plan for updates according to your standard maintenance processes.

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.