CVE-2021-21428: Openapi-Generator Openapi Generator

High severity, CVSS 7.0. EPSS: 0.4% chance of exploitation in the next 30 days.

Openapi generator is a java tool which allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. openapi-generator-online creates insecure temporary folders with File.createTempFile during the code generation process. The insecure temporary folders store the auto-generated files which can be read and appended to by any users on the system. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Affected products

• Openapi-Generator Openapi Generator: before 5.1.0 (fixed in 5.1.0)

Published 2021-05-10. Last modified 2026-06-17.