JDK-8321319 will disable the automatic execution of annotation processors that are present on the classpath in Java 23+, because of supply chain attack concerns.

This would for instance mean that just adding spring-boot-configuration-processor as a dependency won't do anything until the annotation processor in that artifact is explicitly allowed to run.

I think Spring Boot will need to respond to this change in one way or another, either by documenting how users can deal with this (e.g. maven-compiler-plugin's annotationProcessorPaths, using maven-processor-plugin, or dropping this protection again by setting -proc:full while that's still available) or by configuring javac to execute Spring's (or all?) annotation processors automatically.