CVE-2026-55450 langflow-ai CVE debrief

Who should care

Organizations using Langflow versions prior to 1.9.1 should prioritize patching this vulnerability to prevent potential server space exhaustion and information leaks. Security teams and administrators responsible for Langflow deployments should take immediate action to update to version 1.9.1. Additionally, users of Langflow should be aware of the potential risks associated with this vulnerability.

Technical summary

The vulnerability in Langflow allows unauthenticated users to upload arbitrary data without restrictions, potentially leading to server space exhaustion. The vulnerability is caused by a lack of authentication and authorization for data uploads. The response to the upload request also discloses the absolute path of the uploaded file, which can be used to gather information for further attacks. The CVSS score for this vulnerability is 9.3, indicating a critical severity level. The vulnerability is fixed in Langflow version 1.9.1.

Defensive priority

This vulnerability has a high defensive priority due to its critical severity score and potential for server space exhaustion. Immediate patching to version 1.9.1 is recommended.

Recommended defensive actions

• Update Langflow to version 1.9.1 or later
• Restrict access to Langflow to only authenticated users
• Monitor Langflow server space usage for potential exhaustion
• Review Langflow logs for suspicious upload activity
• Implement additional security measures to prevent information leaks

Evidence notes

The CVE-2026-55450 vulnerability is documented in the official CVE record and NVD detail pages. The vulnerability is caused by a lack of authentication and authorization for data uploads in Langflow versions prior to 1.9.1. The CVSS score for this vulnerability is 9.3, indicating a critical severity level. The vulnerability is fixed in Langflow version 1.9.1.

Official resources