CVE-2026-42048

CRITICAL LAB

Langflow: Path Traversal in Langflow Knowledge Bases API

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-42048. PoCs published by EQSTLab, dwisiswant0.

AI-analyzed exploit summary This repository contains a functional proof-of-concept exploit for CVE-2026-42048, a path traversal vulnerability in Langflow before 1.9.0. The exploit demonstrates arbitrary directory deletion via the bulk delete endpoint `/api/v1/knowledge_bases` by manipulating the `kb_names` parameter.

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 (DELETE /api/v1/knowledge_bases). This occurs because user-supplied knowledge base names are concatenated directly into file paths without proper sanitization or boundary validation. An authenticated attacker can exploit this flaw to delete arbitrary directories anywhere on the server's filesystem, leading to data loss and potential service disruption. This vulnerability is fixed in 1.9.0.

Exploits (2)

github WORKING POC 1 stars
by EQSTLab · pythonpoc
https://github.com/EQSTLab/CVE-2026-42048

This repository contains a functional proof-of-concept exploit for CVE-2026-42048, a path traversal vulnerability in Langflow before 1.9.0. The exploit demonstrates arbitrary directory deletion via the bulk delete endpoint `/api/v1/knowledge_bases` by manipulating the `kb_names` parameter.

Classification
Working Poc 100%
Attack Type
Other
Complexity
Trivial
Reliability
Reliable
Target: Langflow < 1.9.0
Auth required
Prerequisites: authenticated access to the Langflow API · vulnerable Langflow version (< 1.9.0) · filesystem permissions to delete the target directory
devstral-2 · analyzed May 21, 2026 Full analysis →
github WORKING POC 1 stars
by dwisiswant0 · pythonpoc
https://github.com/dwisiswant0/neo-pocs/tree/master/2026/CVE-2026-42048

The repository contains a functional exploit for CVE-2026-42048, demonstrating path traversal in Langflow's Knowledge Bases API. The exploit leverages insecure path concatenation in `create_knowledge_base` and `delete_knowledge_bases_bulk` endpoints to create and delete arbitrary directories on the server.

Classification
Working Poc 100%
Attack Type
Other
Complexity
Trivial
Reliability
Reliable
Target: langflow <= 1.8.4
Auth required
Prerequisites: authenticated user access · Langflow instance with vulnerable version
devstral-2 · analyzed May 14, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 9.6
EPSS 0.0001
EPSS Percentile 3.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Lab Environment

COMMUNITY
Community Lab
docker pull langflowai/langflow:1.8.4

Details

CWE
CWE-22
Status published
Products (3)
langflow/langflow < 1.9.0
langflow-ai/langflow < 1.9.0
pypi/langflow 0 - 1.9.0PyPI
Published May 12, 2026
Tracked Since May 13, 2026