What’s Vulnerable › Vulnerabilities

CVE-2026-55450: Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak

• Severity: critical (CVSS 9.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-06-23 · updated 2026-10-25
• Weakness: CWE-200

Description

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.

Affected products

• IBM Langflow OSS: before 1.9.1 — fixed in 1.9.1

How to fix

Upgrade to a fixed version: IBM Langflow OSS 1.9.1. Check the vendor advisory for mitigations.

References

• https://github.com/langflow-ai/langflow/pull/12831
• https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735
• https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735

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