# Spring Boot v4.0.8

- Product: Spring Boot (https://whatsnew.fyi/product/spring-boot)
- Vendor: Broadcom
- Date: 2026-08-21
- Version: v4.0.8
- Original notes: https://github.com/spring-projects/spring-boot/releases/tag/v4.0.8
- Permalink: https://whatsnew.fyi/product/spring-boot/releases/v4.0.8

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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##### :lady_beetle: Bug Fixes

- Kafka consumer-specific security protocol is not taken into account [#51365](https://github.com/spring-projects/spring-boot/issues/51365)
- Temporary file is not deleted when ExportedImageTar construction fails [#51117](https://github.com/spring-projects/spring-boot/pull/51117)
- spring-boot-h2-console pulls servlet-api as transitive dependency [#51094](https://github.com/spring-projects/spring-boot/issues/51094)
- Methods that return the result of Map#remove are not declared with a `@Nullable` return type [#50972](https://github.com/spring-projects/spring-boot/pull/50972)
- PropertiesLauncher does not log nested archive paths [#50968](https://github.com/spring-projects/spring-boot/pull/50968)
- JarFile is not closed when finding main class from archive [#50949](https://github.com/spring-projects/spring-boot/pull/50949)
- CloudFoundry reactive auto-configuration should not require a WebClient.Builder bean to be defined [#50928](https://github.com/spring-projects/spring-boot/issues/50928)
- Resources are not cleaned up when resolving an image that is not yet present in the builder [#50919](https://github.com/spring-projects/spring-boot/pull/50919)
- Context refresh fails on reactive Cloud Foundry when using Actuator without spring-boot-health [#50916](https://github.com/spring-projects/spring-boot/pull/50916)
- GraphQlWebMvcAutoConfiguration should apply customizers in order [#50908](https://github.com/spring-projects/spring-boot/pull/50908)
- Micrometer registries pin the application context [#50886](https://github.com/spring-projects/spring-boot/pull/50886)
- Context refresh fails when using Actuator on Jersey without spring-boot-health [#50858](https://github.com/spring-projects/spring-boot/pull/50858)
- Context refresh fails on Cloud Foundry when using Actuator without spring-boot-health [#50857](https://github.com/spring-projects/spring-boot/pull/50857)
- IllegalStateException when binding properties to a `@Validated` class that contains a map whose value type is a wildcard [#50798](https://github.com/spring-projects/spring-boot/pull/50798)
- Setting 'server.servlet.session.cookie.partitioned' to false still emits the 'Partitioned' cookie attribute [#50781](https://github.com/spring-projects/spring-boot/pull/50781)
- Application-managed JUL bridge handler should only be removed if installed [#50779](https://github.com/spring-projects/spring-boot/pull/50779)
- Inconsistent handling of empty string values of spring.security.oauth2.resourceserver.jwt issuer-uri and jwk-set-uri [#50755](https://github.com/spring-projects/spring-boot/pull/50755)
- PropertiesWebClientHttpServiceGroupConfigurer has highest precedence, preventing other configurers from being ordered ahead of it [#50737](https://github.com/spring-projects/spring-boot/pull/50737)
- High number of connections due to Mongo health indicator [#50734](https://github.com/spring-projects/spring-boot/pull/50734)
- Return type nullability of ApplicationContextAssert's getBean methods does not indicate that bean may be null [#50701](https://github.com/spring-projects/spring-boot/pull/50701)
- NativeImageResourceProvider flattens Flyway migration paths in subdirectories [#50433](https://github.com/spring-projects/spring-boot/pull/50433)
- Fix ordering of Kotlinx Serialization CodecCustomizer [#50428](https://github.com/spring-projects/spring-boot/pull/50428)
- Metadata annotation processor ignores getter-level `@NestedConfigurationProperty` for records [#50096](https://github.com/spring-projects/spring-boot/issues/50096)

##### :notebook_with_decorative_cover: Documentation

- spring.profiles.group should have a 'spring-profile-name' hint provider [#51273](https://github.com/spring-projects/spring-boot/issues/51273)
- Remove reference to removed InfluxDB auto-configuration [#51172](https://github.com/spring-projects/spring-boot/pull/51172)
- Use JacksonJsonSerde in Kafka Streams documentation [#51152](https://githu

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