CVE-2026-42867

Langflow: Path Traversal in Knowledge Bases API via Creation Endpoint

MEDIUM
6.5
CVSS Score
Published: June 23, 2026 at 04:29 PM UTC
Updated: October 26, 2026 at 11:10 AM UTC
2 products affected across 2 vendorsLangflowLangflow

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.5%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.9.0
Affected range stops below 1.9.0, so it looks safe — our inference, not a vendor statement
v < 1.9.0
Affected range stops below 1.9.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/langflow-ai/langflow/security/advisories/GHSA-79ph-745m-6wxq
x_refsource_MISCPatchIssue Tracking
Source: cverecord
https://github.com/langflow-ai/langflow/pull/12337

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-22

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