What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-06-23 · updated 2026-10-26
• Weakness: CWE-22

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.

Affected products

• IBM Langflow OSS: before 1.9.0 — fixed in 1.9.0

How to fix

Upgrade to a fixed version: IBM Langflow OSS 1.9.0. Check the vendor advisory for mitigations.

References

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

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