Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, an Insecure Direct Object Reference (IDOR) vulnerability in /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. 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, an Insecure
    Direct Object Reference (IDOR) vulnerability in /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.
    This vulnerability is fixed in 1.9.1. (CVE-2026-55255)

ID	Name	Product	Family	Type	Severity
326241	Langflow < 1.9.1 Multiple Vulnerabilities	Nessus	Artificial Intelligence	Combined	critical
115276	Langflow < 1.9.1 Multiples Vulnerabilities	Web App Scanning	Artificial Intelligence	Version Based	critical
443659	SCA: security update for langflow (GHSA-qrpv-q767-xqq2)	Tenable Cloud Security	SCA Checks	Local	high
443659	SCA: security update for langflow (GHSA-qrpv-q767-xqq2)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

Detections

Analytics

CVE-2026-55255

high

Tenable Plugins

critical

critical

high

high