Medium severity · published Jun 23, 2026
CVE-2026-42867
Langflow: Path Traversal in Knowledge Bases API via Creation Endpoint
6.5
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LA
langflow · langflow-ai
< 1.9.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42867
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42867
Patch
https://github.com/langflow-ai/langflow/pull/12337
Exploit
https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq
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