Path Traversal in Langflow
CVE-2026-42867
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.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.005 (39.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.
Affected products
- Langflow
- Langflow-ai Langflow — versions < 1.9.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
Frequently asked questions
- What is CVE-2026-42867?
- CVE-2026-42867 is a medium-severity vulnerability in Langflow, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-06-23.
- How severe is CVE-2026-42867?
- Medium severity. CVSS v3 base score is 6.5 out of 10.