CVE-2026-104309 in Langflow OSS
Summary
by MITRE • 10/29/2026
IBM Langflow OSS 1.0.0 through 1.12.3 could allow a remote authenticated attacker to obtain sensitive information due to improper limitation of a pathname to a restricted directory.
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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 file system paths, specifically classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. This category of vulnerabilities is commonly known as path traversal or directory traversal attacks. In this specific instance, the software fails to adequately sanitize or validate user-supplied input that dictates which files are accessed by the application. When an authenticated attacker provides a maliciously crafted pathname containing sequences such as dot-dot-slash (../) or other platform-specific escape characters, the underlying file system operations interpret these sequences not as literal filename components but as instructions to navigate up the directory hierarchy from the intended restricted location.
This technical flaw allows the remote authenticated user to bypass access controls that are designed to confine file operations within a specific sandboxed or protected directory structure. By manipulating the path parameter, an attacker can redirect read requests away from the authorized scope and into sensitive areas of the server's filesystem where configuration files, environment variables containing secrets, database credentials, or other proprietary application data may reside. The authentication requirement indicates that this is not an unauthenticated remote code execution vector but rather a privilege escalation or information disclosure vulnerability accessible to any user who has valid login credentials within the Langflow ecosystem. This distinction is crucial for threat modeling, as it limits the attack surface to authenticated users but significantly increases the potential impact of those compromised accounts.
The operational impact of this vulnerability centers on unauthorized data exfiltration and potential compromise of broader system security. If an attacker successfully exploits this path traversal flaw, they can retrieve sensitive information that was never intended for public or user-level access. This could include internal API keys, database connection strings, private encryption keys, or source code containing hardcoded secrets. The exposure of such credentials often leads to secondary attacks where the compromised data is used to pivot into other systems within the network infrastructure. Furthermore, depending on how Langflow integrates with external services or executes workflows based on loaded configurations, this information disclosure could facilitate more severe outcomes, including remote code execution if sensitive configuration files are modified via related write vulnerabilities, though the primary risk here remains confidentiality breach.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK technique T1083: File and Directory Discovery, which describes adversaries searching for specific data on compromised systems to aid in further exploitation. The lack of strict input validation against path traversal sequences is a common oversight in web applications that handle file uploads or downloads without implementing robust allow-listing strategies. To mitigate this risk, IBM has released updated versions beyond 1.12.3 which address the improper limitation of pathname restrictions. Organizations running affected versions should prioritize immediate patching to the latest stable release. In addition to updating software, administrators should implement defense-in-depth measures such as using chroot jails or containerization to isolate file system access, enforcing strict input validation on all server-side parameters handling file paths, and applying least-privilege principles so that even if a traversal occurs, the process lacks permissions to read critical system files. Regular security audits focusing on CWE-22 patterns are recommended for any application managing user-controlled file operations.