CVE-2026-79723 in Langflow OSS
Summary
by MITRE • 09/11/2026
IBM Langflow OSS 1.0.0 through 1.11.5 could allow a remote authenticated attacker to obtain sensitive information due to improper validation of user-controlled API endpoints.
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Analysis
by VulDB Data Team • 09/11/2026
The vulnerability identified in IBM Langflow versions 1.0.0 through 1.11.5 represents a significant security flaw rooted in the inadequate validation and sanitization of user-supplied input directed at application programming interface endpoints. As an open-source framework designed for building large language model applications, Langflow exposes various API routes that facilitate interaction with its core functionalities. The specific weakness lies in how these endpoints process requests from authenticated users who possess valid credentials to access the platform. While authentication serves as a primary barrier against unauthorized access, it does not inherently guarantee safe handling of data provided by those authorized entities. In this instance, the application fails to rigorously validate or sanitize inputs before processing them through internal logic that may expose sensitive system information. This lack of proper input validation allows an attacker who has already authenticated into the system to craft specific requests that exploit these unchecked pathways.
From a technical perspective, this flaw aligns with CWE-20 Improper Input Validation and potentially CWE-798 if it leads to unauthorized access to credentials or sensitive configuration data. The vulnerability enables what is known as an Insecure Direct Object Reference scenario where the application does not sufficiently verify that the user has permission to access specific resources or retrieve particular types of metadata associated with those endpoints. By manipulating API parameters, a remote authenticated attacker can trigger responses that return internal details such as database structures, configuration settings, environment variables, or other proprietary information critical to the operation of the Langflow instance and any connected LLM services. This type of flaw is particularly dangerous because it leverages legitimate access rights to escalate privileges in terms of data exposure without requiring a breach of authentication mechanisms.
The operational impact of this vulnerability extends beyond simple data leakage. If sensitive configuration details or internal API keys are exposed, an attacker could use this information to further compromise the underlying infrastructure hosting Langflow. This might include gaining unauthorized access to connected vector databases, cloud storage buckets, or other microservices that rely on credentials stored within the application environment. Furthermore, exposure of such information can facilitate more sophisticated attacks by providing insights into the technology stack and internal architecture, thereby aiding in the planning of subsequent exploitation attempts against related systems. The ability to retrieve sensitive information remotely with authenticated access significantly lowers the barrier for entry for malicious actors who may have obtained credentials through phishing or other means, turning a standard user account into a powerful tool for reconnaissance and potential data exfiltration.
To mitigate this risk, immediate action is required by upgrading IBM Langflow to version 1.12.0 or later where these validation checks have been strengthened. For organizations unable to upgrade immediately due to compatibility constraints with existing workflows, implementing strict input validation rules at the API gateway level can provide a temporary layer of defense. This involves ensuring that all incoming requests are sanitized against expected formats and lengths before they reach the application logic. Additionally, applying the principle of least privilege is crucial; administrators should ensure that authenticated users have only the minimum necessary permissions to perform their required tasks, thereby limiting the scope of data accessible through any potential exploitation vector. Regular security audits and penetration testing focused on API endpoints are also recommended to identify similar weaknesses in input handling across other parts of the application ecosystem.