Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.

The version of Langflow installed on the remote host is prior to 1.9.1. It is, therefore, affected by multiple vulnerabilities:

  - An Insecure Direct Object Reference (IDOR) vulnerability in the /api/v1/responses     endpoint allows an authenticated attacker to execute any flow belonging to another user     by specifying the victim's flow ID in the request. (CVE-2026-55255)

  - Unauthenticated users can upload any amount of data to the server without any limitations,     requiring only network access to Langflow. This can lead to space exhaustion on the server.
    In addition, the absolute path of the uploaded file is reported in the response, which is     an information leak that can assist in chaining other attack primitives. (CVE-2026-55450)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

According to its banner, the version of Langflow running on the remote host is prior to 1.9.1. It is, therefore, affected by a multiples vulnerabilities :

- An Indirect Object Reference (IDOR) in /api/v1/responses that allows authenticated attacker to access another user's Flow

- An Unauthenticated file upload that an lead to a Denial Of Service (DoS)and information leak

Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1,
    unauthenticated users can upload any amount of data to the server without any limitations. No need for any
    prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In
    addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an
    information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.
    (CVE-2026-55450)

ID	Name	Product	Family	Severity
326241	Langflow < 1.9.1 Multiple Vulnerabilities	Nessus	Artificial Intelligence	critical
115276	Langflow < 1.9.1 Multiples Vulnerabilities	Web App Scanning	Artificial Intelligence	critical
443350	SCA: security update for langflow (GHSA-x223-p2gf-v735)	Tenable Cloud Security	SCA Checks	critical
443350	SCA: security update for langflow (GHSA-x223-p2gf-v735)	Tenable Self-Hosted Container Security	SCA Checks	critical

Detections

Analytics

CVE-2026-55450

critical

Tenable Plugins

critical

critical

critical

critical