PT-2026-50139

CVE-2026-33760

Published

2026-06-16

Updated

2026-06-24

Description by

CVSS 3.1

8.8

High

MetricsAV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Langflow versions prior to 1.9.0

Description The /api/v1/monitor router exposes seven endpoints that allow read, write, and delete operations on user-owned resources, including messages, sessions, build artifacts, and LLM transaction logs. The system fails to verify if the authenticated requester owns the targeted resource, leading to an Insecure Direct Object Reference (IDOR), also known as Broken Object Level Authorization (BOLA). An authenticated user can read, modify, rename, or permanently delete another user's data by providing the target's resource ID or flow id.

Technical details include the following vulnerable endpoints:

'GET /api/v1/monitor/builds' and 'DELETE /api/v1/monitor/builds' using the flow id variable.
'DELETE /api/v1/monitor/messages' using the message ids variable.
'PUT /api/v1/monitor/messages/{message id}' using the message id variable.
'PATCH /api/v1/monitor/messages/session/{old session id}' using the old session id variable.
'DELETE /api/v1/monitor/messages/session/{session id}' using the session id variable.
'GET /api/v1/monitor/transactions' using the flow id variable.

Recommendations Update to version 1.9.0. As a temporary workaround, restrict access to the /api/v1/monitor endpoints to minimize the risk of unauthorized data access or deletion.

Exploitability

Exploit

Fix

Impacts

Researchers

Akshatgit

Ethansilvas

Yzeirnials

Vendors

Affected products

Weakness enumeration

CWE-639: Authorization Bypass Through User-Controlled Key