CVE-2026-42867
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk20th percentile — higher than 20% of all known CVEs
Summary
Langflow before version 1.9.0 contains a Path Traversal vulnerability in the Knowledge Bases API (POST /api/v1/knowledge_bases). An authenticated attacker can exploit the lack of input sanitization to create directories and write files anywhere on the server's filesystem.
Risk Assessment
The risk includes unauthorized file writes, which could lead to server compromise, modification of critical system files, or execution of malicious code.
Recommendation
Immediately update Langflow to version 1.9.0 or later. If updating is not possible, restrict access to the Knowledge Bases API to trusted users and implement additional path validation mechanisms.
Original NVD description (English source)
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.0, Langflow is vulnerable to Path Traversal in the Knowledge Bases API (POST /api/v1/knowledge_bases). This occurs because user-supplied knowledge base names are used directly to create file paths without proper sanitization or containment checks. An authenticated attacker can exploit this flaw to create directories and write files anywhere on the server's filesystem. This vulnerability is fixed in 1.9.0.