Spring Boot 4.2.0-RC1
Spring Boot 4.2.0-RC1 is out with 113 enhancements, fixes, and dependency upgrades. https://spring.io/blog/2026/10/23/spring-boot-4-2-0-RC1-available-now Highlights: faster startup thanks to quicker class/resource lookup in executable jars, a new default Buildpacks builder based on Ubuntu 26.04, and a properties migrator that can now fail the app on errors or warnings.