CVE-2026-55446 Langflow: Unauthenticated DoS through multipart form boundary file upload

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.0.19, an attacker can send a /api/v1/files/upload/ request without any authentication token/cookies and abuse a very long multipart form boundary to make the langflow app unusable for all users for an...

CVE-2026-55446

Langflow before version 1.0.19 is vulnerable to unauthenticated DoS on the /api/v1/files/upload/ endpoint by sending a multipart/form-data request with an extremely long boundary. The vulnerability allows an attacker to cause the server to become unusable for all users for an indefinite period, w...