CVE-2026-42867Langflow: Path Traversal in Knowledge Bases API via Creation Endpoint

Description

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq ExploitVendor Advisory
• https://github.com/langflow-ai/langflow/pull/12337 PatchIssue Tracking