Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M
CVE-2026-55450Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak
Critical 9.3
In plain English
A critical-severity information exposure in langflow from langflow-ai. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 68% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langflow | 1.9.1 | GHSA-x223-p2gf-v735 |
| PyPI | langflow | 1.9.1 | PYSEC-2026-224 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langflow-ai | langflow | < 1.9.1 |
Weakness: CWE-200, CWE-306, CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
References
- https://github.com/langflow-ai/langflow/security/advisories/GHSA-x223-p2gf-v735 x_refsource_CONFIRM
- https://github.com/langflow-ai/langflow/pull/12831 x_refsource_MISC