Critical IBM Langflow OSS Flaw Allows RCE

A critical security vulnerability, tracked as CVE-2026-9202 (GHSA-f8j5-5w75-w786), has been identified in IBM Langflow OSS versions 1.0.0 through 1.10.0. This flaw allows unauthenticated attackers to create unlimited user accounts, and if the NEW_USER_IS_ACTIVE configuration is enabled, these accounts gain immediate access to remote code execution (RCE) endpoints.

What's at Risk

The vulnerability affects all deployments of IBM Langflow OSS within the specified version range. Organizations that have deployed these instances with the NEW_USER_IS_ACTIVE=true setting are at the highest risk, as the barrier to entry for an attacker is effectively removed.

Generally, internet-facing applications that allow unauthenticated registration or account creation are highly susceptible to automated exploitation. Any organization utilizing this software in a production or development environment should consider their instances exposed until they have verified their patch status or implemented compensating controls.

How the Flaw Works

This vulnerability falls into the category of Broken Access Control. In general terms, this class of weakness occurs when an application fails to properly verify the identity or permissions of a user before granting access to sensitive functions or administrative endpoints. When authentication mechanisms can be bypassed or manipulated to create unauthorized accounts, an attacker can elevate their privileges to those of an authenticated user or even an administrator.

By gaining unauthorized access to the system, an attacker can typically interact with backend APIs or internal tooling that was intended to be restricted. In the context of RCE, this often involves the ability to submit malicious input to system-level functions or configuration interfaces, allowing the attacker to execute arbitrary commands on the underlying server infrastructure.

How to Protect Your Systems

• Immediately audit your IBM Langflow OSS instances for unauthorized user accounts.
• Upgrade to a version of IBM Langflow OSS that patches this vulnerability as soon as a fix is available from the vendor.
• Ensure that the NEW_USER_IS_ACTIVE setting is disabled unless explicitly required by your business needs.
• Restrict network access to your Langflow instances using firewalls or VPNs to prevent public internet exposure.
• Implement multi-factor authentication (MFA) where possible to add a layer of security to the authentication process.
• Monitor system logs for suspicious account creation activities or unauthorized access attempts.

Given the CVSS score of 9.8 and the potential for full system compromise, the urgency of addressing this vulnerability cannot be overstated. Organizations must prioritize the identification and remediation of affected Langflow instances to prevent exploitation and maintain the integrity of their internal environments.