Grails is a framework used to build web applications with the Groovy programming language. A specially crafted web request can lead to a JVM crash or denial of service. Any Grails framework application using Grails data binding is vulnerable. This issue has been patched in version 3.3.17, 4.1.3, 5.3.4, 6.1.0.
In grails-databinding in Grails before 3.3.15, 4.x before 4.1.1, 5.x before 5.1.9, and 5.2.x before 5.2.1 (at least when certain Java 8 configurations are used), data binding allows a remote attacker to execute code by gaining access to the class loader.