File.createTempFile in JDK will result in creating and using insecure temporary files that can leave application and system data vulnerable to attacks. This vulnerability only impacts unix-like systems where the local system temporary directory is shared between all users. This vulnerability does not impact Windows or modern versions of MacOS.
OpenAPI Generator Maven plug-in creates insecure temporary files during the code generation process. It creates insecure temporary files to store the OpenAPI specification files provided by the users and these temporary files can be read by any users in the system.
The impact of this vulnerability is information disclosure of the contents of the specification file to other local users.
The issue has been patched with
Files.createTempFile and released in the v5.1.0 stable version.