CVE-2026-17621 in Langflow OSS
Summary
by MITRE • 09/04/2026
IBM Langflow OSS 1.0.0 through 1.10.2 could allow a remote attacker to traverse directories on the system. An attacker could send a specially crafted URL request containing "dot dot " sequences ( /.. /) to view arbitrary files on the system.
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Analysis
by VulDB Data Team • 09/04/2026
The vulnerability identified in IBM Langflow versions 1.0.0 through 1.10.2 represents a critical directory traversal flaw that compromises the integrity and confidentiality of the underlying file system. This security defect arises from insufficient validation or sanitization of user-supplied input within URL requests, specifically targeting path parameters handled by the application's web interface. When an attacker constructs a malicious request containing dot-dot-slash sequences such as /../, they can manipulate the intended directory structure to access files and directories that reside outside the restricted root folder designated for public or safe content. This type of vulnerability is classically categorized under CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which highlights the failure to enforce strict boundaries on file system operations based on external input.
From an operational perspective, this flaw allows remote attackers who have network access to the Langflow instance to read arbitrary files from the host operating system. The impact is severe because it can lead to the exposure of sensitive configuration files, environment variables containing credentials or API keys, source code repositories, and other proprietary data stored on the server. In many deployment scenarios, web applications run with specific user privileges that may still have access to critical system resources. By leveraging this directory traversal technique, an attacker does not necessarily need to exploit a separate authentication bypass; they simply need valid network connectivity to the application endpoint vulnerable to path manipulation. This capability effectively neutralizes any file isolation mechanisms intended by the application architecture, turning local file read operations into remote information disclosure vectors.
The exploitation of this vulnerability aligns with techniques observed in real-world attack scenarios where adversaries seek initial access or reconnaissance phases within a compromised environment. Specifically, it relates to ATT&CK technique T1083: File and Directory Discovery, which describes methods used by attackers to enumerate files and directories on local systems for further exploitation or data exfiltration. The ability to view arbitrary files can serve as a stepping stone for more advanced attacks, such as reading private keys to impersonate services or discovering database configuration details to initiate SQL injection campaigns against backend storage components. Consequently, the risk extends beyond simple information disclosure into potential full system compromise if combined with other vulnerabilities in the stack.
To mitigate this vulnerability, immediate action is required by upgrading IBM Langflow to a version later than 1.10.2 where the path handling logic has been corrected to properly sanitize and validate input paths before processing them against the file system. Administrators should ensure that all instances of affected software are patched promptly. In addition to patching, defense-in-depth strategies should be employed, such as configuring web servers or reverse proxies to reject requests containing suspicious patterns like dot-dot-slash sequences at the network edge. Furthermore, running application services with minimal necessary privileges and utilizing chroot jails or containerization limits can reduce the blast radius if a traversal attempt succeeds. Regular security audits and static code analysis tools should be integrated into the development lifecycle to detect similar input validation weaknesses in future releases of Langflow or related components.