CVE-2026-19304 in Langflow OSS
Summary
by MITRE • 09/04/2026
IBM Langflow OSS 1.0.0 through 1.11.2 could allow a remote authenticated attacker to obtain sensitive information from internal services due to a URL parser discrepancy.
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Analysis
by VulDB Data Team • 09/04/2026
The vulnerability identified in IBM Langflow versions 1.0.0 through 1.11.2 represents a significant security risk stemming from an improper validation of Uniform Resource Locators within the application's core processing logic. This flaw is classified under CWE-601, which describes URL Redirection to Untrusted Site, but in this specific context, it manifests as a mechanism for accessing internal services that are not intended to be exposed to external networks or authenticated users. The root cause lies in how the software parses and resolves URLs provided by the user during API interactions or interface operations. When an attacker provides a specially crafted URL input, the application fails to adequately distinguish between public internet resources and private internal endpoints, such as those located on localhost or within the local network segment where Langflow is deployed.
From a technical perspective, this discrepancy allows for server-side request forgery-like behavior where the authenticated user can instruct the backend service to make requests to arbitrary destinations. Because the vulnerability relies on URL parsing errors rather than complex injection techniques, it is relatively straightforward to exploit using standard HTTP clients or web browsers once authentication credentials are obtained. The attacker leverages their valid session token to send a request containing a maliciously formatted URL that targets internal management interfaces, database ports, or other sensitive microservices running within the same environment as Langflow. This bypasses network-level security controls like firewalls because the requests originate from inside the trusted perimeter, effectively treating them as legitimate administrative traffic.
The operational impact of this vulnerability is severe for organizations relying on IBM Langflow for managing large language model workflows and data pipelines. An authenticated attacker can use this flaw to enumerate internal services, extract sensitive configuration details, or potentially pivot further into the network by accessing unauthenticated endpoints that are typically protected from external access. This leads to a compromise of confidentiality integrity within the deployment environment. In scenarios where Langflow is integrated with other enterprise systems, such as cloud storage providers or internal data lakes, this exposure could lead to unauthorized data retrieval or manipulation. The ability to interact with these internal services undermines the principle of least privilege and exposes critical infrastructure components that were assumed to be secure behind authentication layers.
To mitigate this risk, organizations running affected versions must immediately upgrade IBM Langflow to version 1.12.0 or later, where the URL parsing logic has been hardened to strictly validate destination hosts against a whitelist of allowed domains or explicitly block private IP ranges and loopback addresses. Until an update is applied, administrators should implement strict network segmentation policies that isolate the Langflow deployment from sensitive internal services using firewall rules or zero-trust architecture principles. Additionally, deploying Web Application Firewalls with specific rule sets to detect and block outbound requests targeting non-public IP address spaces can provide a layer of defense in depth. It is also critical to enforce strong authentication mechanisms and monitor logs for unusual outbound connection patterns originating from the Langflow application server to detect potential exploitation attempts early.