CVE-2021-21430: Openapi-Generator Openapi Generator

Medium severity, CVSS 5.5. EPSS: 0.4% chance of exploitation in the next 30 days.

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec. Using `File.createTempFile` in JDK will result in creating and using insecure temporary files that can leave application and system data vulnerable to attacks. Auto-generated code (Java, Scala) that deals with uploading or downloading binary data through API endpoints will create insecure temporary files during the process. Affected generators: `java` (jersey2, okhttp-gson (default library)), `scala-finch`. The issue has been patched with `Files.createTempFile` and released in the v5.1.0 stable version.

Affected products

• Openapi-Generator Openapi Generator: before 5.1.1 (fixed in 5.1.1)

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