CVE-2026-7658 in Langflow OSS
Summary
by MITRE • 08/05/2026
IBM Langflow OSS 1.0.0 through 1.10.3 does not properly validate the username field, allowing attackers to inject path traversal sequences and bypass containment checks. This enables multiple severe impacts, including arbitrary directory deletion, cross-tenant data destruction, and JWT signing key deletion leading to session invalidation.
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Analysis
by VulDB Data Team • 08/05/2026
The vulnerability in IBM Langflow Open Source Software versions 1.0.0 through 1.10.3 represents a critical path traversal flaw that stems from insufficient input validation of the username field. This weakness allows malicious actors to manipulate the authentication and authorization mechanisms by injecting directory traversal sequences such as ../ or ..\ into the username parameter. The root cause of this vulnerability aligns with CWE-22 Path Traversal and CWE-352 Cross-Site Request Forgery, creating a dangerous intersection where improper validation leads to unauthorized system access and data manipulation capabilities.
The technical exploitation of this vulnerability enables attackers to bypass containment checks that are designed to restrict user access to specific directories or resources. When the username field is not properly sanitized, the application processes these traversal sequences as legitimate path components rather than malicious input, allowing unauthorized access to system files and directories beyond the intended scope. This flaw operates at the application level where user-supplied data should be strictly validated before being used in file system operations or directory navigation functions.
The operational impact of this vulnerability is severe and multifaceted, encompassing multiple attack vectors that can lead to catastrophic system compromise. Attackers can leverage this weakness to perform arbitrary directory deletion operations, effectively destroying critical system components or user data. Additionally, the vulnerability enables cross-tenant data destruction, where malicious actors can access and manipulate resources belonging to other users or tenants within the same system, violating fundamental isolation principles in multi-tenant environments. The most critical aspect involves JWT signing key deletion, which results in immediate session invalidation across the entire platform and undermines the authentication infrastructure.
This vulnerability exposes significant gaps in the application's security architecture and follows patterns commonly associated with ATT&CK technique T1059 Command and Scripting Interpreter and T1213 Data from Information Repositories. The attack chain typically begins with username field manipulation followed by path traversal exploitation, leading to privilege escalation and data destruction. Organizations implementing IBM Langflow OSS in production environments face immediate risk of unauthorized access, data loss, and potential system compromise if this vulnerability remains unpatched.
Mitigation strategies should include immediate implementation of strict input validation for all user-supplied data, particularly username fields, where directory traversal sequences must be explicitly rejected or sanitized before processing. The application should enforce proper path normalization and validation routines that prevent any form of path traversal exploitation attempts. Organizations should also implement comprehensive monitoring and logging of file system operations to detect suspicious activities related to directory manipulation. Additionally, privilege separation mechanisms should be strengthened to ensure that user operations cannot affect critical system directories or authentication components such as JWT signing keys. The most effective remediation involves applying the vendor-provided patches or upgrading to versions that have addressed this vulnerability through proper input validation and containment controls.
The broader implications of this vulnerability highlight the importance of secure coding practices in open source software development, particularly regarding input validation and privilege management. This flaw demonstrates how seemingly simple validation issues can lead to complex security breaches with cascading effects throughout the system architecture, affecting not only individual user data but also the overall platform integrity and user trust in the application's security posture.