External risk intelligence

IBM Langflow OSS Code Injection Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-81204

IBM Langflow is a web-based tool used for building workflows and applications. These systems are commonly deployed as web interfaces or API services accessible over a network, making them likely to be reachable in many deployment 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 that could allow an attacker to execute arbitrary code remotely due to code injection during the construction of graphs. This issue affects a web-based tool commonly deployed as an accessible service, potentially exposing systems to significant risk.

Code injection allows remote code execution.
Critical remote code execution flaw identified.
Confirm relevance and exposure of this tool.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted input to an exposed instance of IBM Langflow over a network. This input would be processed during the construction of a data graph, leading to code injection. If successful, an attacker could execute arbitrary code on the affected system.

No special access required.
Graph construction process.
Arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

A critical vulnerability in IBM Langflow OSS, when supported by the advisory, could allow a remote attacker to execute arbitrary code due to code injection during graph construction. This means an attacker could potentially inject malicious code into the system's workflow construction process, leading to unauthorized command execution.

Arbitrary code execution.
Code injection during graph construction.
Compromise of service and data.

Operational Fix

Recommended remediation, mitigation, and detection steps

IBM Langflow OSS, used for building workflows and applications, is likely managed by application owners or platform teams. The first step is to identify all instances of Langflow, assess their reachability and criticality, and confirm the accountable owner for each. This will inform a risk-based remediation plan.

Application owners should prioritize this issue.
Verify Langflow instances and their exposure.
Plan remediation based on identified risk.

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?

IBM Langflow OSS is an open-source, web-based platform designed to help users visually build, prototype, and deploy complex AI workflows and data applications. It serves as an interactive environment where developers connect various components into functional graphs, often running as an API service or web interface to handle data processing tasks.

What does code injection mean for CVE-2026-81204?

This vulnerability involves a weakness classified as CWE-94, or Improper Control of Generation of Code. In the context of CVE-2026-81204, it means the application does not sufficiently validate the input used to build data graphs. An attacker can exploit this by injecting their own instructions, which the system then executes as if they were legitimate parts of the workflow.

How is this vulnerability triggered?

An attacker triggers the flaw by sending specially crafted input to a Langflow instance. The malicious code is processed specifically during the graph construction phase, where the application interprets the user-provided data. This flaw is not triggered by standard, non-malicious interactions or general usage of the platform that does not involve the construction of these data graphs.

Is my IBM Langflow instance at risk?

Halo Surface Signal identifies Langflow instances as highly likely to be reachable over a network, such as the internet. If your instance is exposed to external networks or accessible by untrusted users, it faces a higher risk. You should determine if your deployment is reachable via public-facing network paths rather than being restricted to a secure, private internal network.

What should I do to secure my environment?

Begin by creating a complete inventory of all IBM Langflow OSS instances within your organization. Identify who is responsible for each deployment and verify their current network exposure. Once accounted for, prioritize these systems for updates or isolation based on their function and accessibility, ensuring you have a clear plan to apply forthcoming patches.

References

www.ibm.com/support/pages/node/7286666

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.