What is CVE-2026-42048?

CVE-2026-42048 is a critical-severity vulnerability in Langflow, classified under Path Traversal. CVSS score: 9.6/10. Published 2026-05-12.

How severe is CVE-2026-42048?

Critical severity. CVSS v3 base score is 9.6 out of 10.

Is CVE-2026-42048 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Path Traversal in Langflow

CVE-2026-42048

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.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.044 (90.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H.

Affected products

Langflow
Langflow-ai Langflow — versions < 1.9.0

Weakness classification (CWE)

CWE-22 — Path Traversal

Public proof-of-concept exploits

EQSTLab/CVE-2026-42048

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42048?: CVE-2026-42048 is a critical-severity vulnerability in Langflow, classified under Path Traversal. CVSS score: 9.6/10. Published 2026-05-12.
How severe is CVE-2026-42048?: Critical severity. CVSS v3 base score is 9.6 out of 10.
Is CVE-2026-42048 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.