CVE-2026-55450
Langflow: Unauthenticated file upload leads to DoS (space exhaustion) and information leak
- Published
- Jun 23, 2026
- Updated
- Jun 23, 2026
- Assigning CNA
- GitHub_M
- Evidence observed
- Oct 9, 2026
Primary CVSS
nvd · CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:HLow · next 30 days
- Percentile
- 67.0%
- Model date
- Oct 7, 2026
EPSS is a statistical estimate, not a certainty or a measure of impact. Combine it with CVSS, KEV status, exposure and your environment.
Summary
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.
Sources
http/cves/2026/CVE-2026-55450.yaml
Nuclei TemplatesDeclared conditions
- network: http($.protocol_keys)
- verification: dsl($.matchers[*].type)
- CVE-2026-55450Informational
Advisory documenting CVE-2026-55450, an unauthenticated file upload flaw in Langflow, with impact analysis, detection references, and remediation guidance.
Responsible use
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