langflow-ai langflow up to 1.8.x Transaction /api/v1/monitor authorization

Summaryinfo

A vulnerability labeled as very critical has been found in langflow-ai langflow up to 1.8.x. Affected by this issue is some unknown functionality of the file /api/v1/monitor of the component Transaction Handler. Such manipulation leads to authorization. This vulnerability is documented as CVE-2026-33760. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in langflow-ai langflow up to 1.8.x and classified as very critical. Affected by this issue is an unknown part of the file /api/v1/monitor of the component Transaction Handler. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.0, Langflow's /api/v1/monitor router exposes 7 endpoints that perform read, write, and delete operations on user-owned resources — messages, sessions, build artifacts, and LLM transaction logs — without verifying that the authenticated requester owns the targeted resource. Any authenticated user can read, modify, rename, or permanently delete another user's data by supplying the target's resource ID or flow_id. This is a classic IDOR/BOLA vulnerability. Notably, the same source file (monitor.py) contains one correctly-implemented endpoint that uses an ownership check, demonstrating the correct pattern was known but inconsistently applied. This vulnerability is fixed in 1.9.0.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-33760 since 03/23/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/24/2026).

Upgrading to version 1.9.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-38519). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Artificial Intelligence Software

Vendor

• langflow-ai

Name

• langflow

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8

Website

• Product: https://github.com/langflow-ai/langflow/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion