CVE-2026-19302 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 due to improper validation of symbolic links.
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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 flaw rooted in the application's handling of file system operations, specifically regarding symbolic link resolution. This issue falls under the category of improper validation of symbolic links, which is formally classified as CWE-59: Improper Link Resolution Before File Access. In this context, the vulnerability allows an attacker who has already authenticated to the Langflow environment to manipulate how the application resolves file paths during operations such as loading or saving data. By exploiting the lack of strict validation on these symbolic links, a remote authenticated user can bypass intended access controls and traverse directories that they should not have permission to view.
The technical mechanism behind this flaw involves the way the software processes input related to file locations without adequately verifying whether those inputs resolve to legitimate files within expected boundaries or if they point to sensitive system resources elsewhere on the host operating system. When a user provides a path containing symbolic links, the application fails to ensure that the final resolved target remains within an allowed directory structure. This oversight enables what is commonly known as a Path Traversal attack, where the attacker constructs malicious file paths that escape the sandboxed or restricted areas designated for Langflow operations. Consequently, this can lead to unauthorized read access to sensitive configuration files, environment variables containing credentials, source code of other applications running on the same host, or any other data stored in locations outside the intended scope of the application's user account privileges.
From an operational impact perspective, while the requirement for authentication limits the attack surface compared to unauthenticated remote exploits, the severity remains high due to the potential for information disclosure within enterprise environments where Langflow is often deployed as part of larger AI or data processing pipelines. An attacker who gains access through compromised credentials can leverage this vulnerability to extract sensitive intellectual property, internal network topology details embedded in configuration files, or authentication tokens stored on disk. This information could subsequently be used for further lateral movement within the organization's infrastructure, privilege escalation attacks against other services running with higher privileges, or social engineering campaigns targeting administrators based on exposed internal data structures. The ability to read arbitrary files effectively breaks the isolation guarantees expected of containerized or sandboxed application environments, undermining the security posture provided by deployment architectures such as Kubernetes pods or isolated virtual machines if those containers share underlying storage volumes without proper restrictions.
To mitigate this vulnerability, organizations running affected versions of IBM Langflow must prioritize immediate patching to version 1.12.0 or later where these path validation mechanisms have been corrected. In the interim, before an upgrade can be performed, administrators should implement strict network segmentation to limit access to the Langflow instance only from trusted subnets and enforce strong multi-factor authentication for all user accounts to reduce the risk of credential compromise leading to exploitation. Additionally, deploying Web Application Firewalls with rules specifically tuned to detect path traversal patterns such as double-dot sequences or encoded slash characters can provide a layer of defense in depth. It is also critical to review file system permissions on the host machine hosting Langflow, ensuring that the application runs under a least-privilege user account with minimal read access to directories outside its own working directory. Regular auditing of symbolic links within the deployment environment and disabling unnecessary symlink creation capabilities at the operating system level can further reduce the attack surface associated with this class of vulnerabilities.
This incident highlights the importance of rigorous input validation in applications that interact heavily with the file system, a principle emphasized across various industry standards including OWASP Top 10 which lists Broken Access Control as a critical risk category. The behavior aligns with techniques observed in ATT&CK framework tactics related to Collection and Exfiltration, specifically methods involving local data staging or remote file transfer via compromised systems. By addressing the root cause through software updates and reinforcing environmental controls, organizations can effectively neutralize this threat vector and maintain the integrity of their AI development workflows within Langflow.