CVE-2026-55450CWE-200CWE-306CWE-400

Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak

Critical · published June 23, 2026

CVSS v3.1
9.3
EPSS
1%
Percentile
67.7
In the wild
Unconfirmed
What it is

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 record
Technical detail
CVSS v3.1
9.3 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.01190 · 67.7th percentile
Weaknesses
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor; CWE-306 · Missing Authentication for Critical Function; CWE-400 · Uncontrolled Resource Consumption
Published
2026-06-23T16:17Z
EPSS history
Timeline
  • 23 JUN 16:17Z
    Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak
    cvelistv5