CVE-2026-42048 Langflow: Path Traversal in Langflow Knowledge Bases API
An authenticated attacker can delete arbitrary directories on the server via path traversal in the Knowledge Bases API, causing data loss and service disruption.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42048?
CVE-2026-42048 is a critical path traversal vulnerability in Langflow Langflow, published on 12 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2026-42048?
3 open source packages ship an affected version, including langflow. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
langflow PyPI | All versions | 1.9.0 |
langflow PyPI | All versions | 1.9.0 |
langflow PyPI | All versions | 1.9.0 |
Products include Langflow Langflow.
How do I fix CVE-2026-42048?
Upgrade langflow to 1.9.0 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-42048 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42048 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Langflow Langflow
Sources
Also known as GHSA-9whx-c884-c68q, PYSEC-2026-377.