CVE-2026-104339 in Langflow OSS
Summary
by MITRE • 10/29/2026
IBM Langflow OSS 1.0.0 through 1.12.3 could allow a remote attacker to execute arbitrary code due to improper neutralization of special elements used in an OS command.
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Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified in IBM Langflow versions 1.0.0 through 1.12.3 represents a critical security flaw rooted in the application's handling of user-supplied input during operating system command execution. This issue is classified as Command Injection, specifically falling under CWE-78 Improper Neutralization of Special Elements used in an OS Command within the Common Weakness Enumeration taxonomy. The core technical failure lies in the insufficient validation and sanitization mechanisms applied to data inputs before they are passed to underlying shell interpreters or system-level command execution functions. When a remote attacker crafts malicious input containing special characters such as semicolons, pipes, ampersands, or backticks, these elements can break out of the intended context and be interpreted by the operating system's command interpreter rather than being treated as literal data strings.
This architectural weakness allows for arbitrary code execution with the privileges associated with the process running Langflow. In many deployment scenarios, this could mean that an attacker gains control over the server hosting the application, potentially leading to a complete compromise of the underlying infrastructure. The operational impact is severe, as it enables unauthorized access to sensitive data stored on or accessible from the compromised system, modification of critical files, and use of the infected machine as a pivot point for further attacks against other network resources. This aligns with the MITRE ATT&CK technique T1059 Command and Scripting Interpreter, where adversaries leverage built-in operating system utilities to execute malicious commands without deploying additional malware binaries, thereby reducing detection likelihood by security monitoring tools that focus on executable file changes.
The exploitation of this vulnerability typically requires a remote attacker to interact with specific endpoints or interfaces within Langflow that accept user input for processing tasks such as data transformation, workflow execution, or integration calls. By injecting shell metacharacters into these inputs, the attacker can chain multiple commands together, bypassing intended logic flows and executing arbitrary system-level operations. This capability undermines the fundamental security principle of least privilege if the application is not running in a restricted environment with minimal permissions. The lack of proper input sanitization suggests that developers may have relied on naive string concatenation or insufficient regex-based filtering rather than employing parameterized execution methods or allow-listing strategies for command arguments.
To mitigate this vulnerability, immediate action must be taken to upgrade IBM Langflow to version 1.12.4 or later, where the issue has been addressed through improved input validation and safer command execution practices. In environments where upgrading is not immediately feasible, defensive measures should include implementing strict allow-listing for any user-supplied parameters that interact with system commands, ensuring that only expected alphanumeric characters are accepted while rejecting all special shell metacharacters. Additionally, deploying the application within a containerized environment with restricted capabilities can limit the blast radius of an successful exploitation attempt. Network-level controls such as web application firewalls may also help detect and block common command injection patterns by analyzing request payloads for suspicious sequences of characters indicative of OS command abuse. Regular security audits and static code analysis focused on CWE-78 are recommended to prevent similar flaws in future development cycles, ensuring that all external inputs are rigorously validated before being processed by the operating system.