In Spring Boot versions 2.7.0 - 2.7.17, 3.0.0-3.0.12 and 3.1.0-3.1.5, it is possible for a user to provide specially crafted HTTP requests that may cause a denial-of-service (DoS) condition.

Specifically, an application is vulnerable when all of the following are true:

the application uses Spring MVC or Spring WebFlux org.springframework.boot:spring-boot-actuator is on the classpath

In Spring Boot versions 3.0.0 - 3.0.5, 2.7.0 - 2.7.10, 2.6.0 - 2.6.14, 2.5.0 - 2.5.14 and older unsupported versions, an application that is deployed to Cloud Foundry could be susceptible to a security bypass.

References:

https://spring.io/security/cve-2023-20873 https://github.com/spring-projects/spring-boot/commit/307f3c339912466e78fcdac648fff95a4edea573 https://github.com/spring-projects/spring-boot/commit/3522714c13b47af03bf42e7f2d5994af568cb1a7 https://github.com/spring-projects/spring-boot/issues/35085 https://github.com/spring-projects/spring-boot/releases/tag/v2.7.11

In Spring Boot versions 3.0.0 - 3.0.6, 2.7.0 - 2.7.11, 2.6.0 - 2.6.14, 2.5.0 - 2.5.14 and older unsupported versions, there is potential for a denial-of-service (DoS) attack if Spring MVC is used together with a reverse proxy cache.

When configured to use an SSL bundle, Spring Boot's RabbitMQ auto-configuration does not perform hostname verification when connecting to the RabbitMQ broker.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14) per vendor advisory.

An attacker on the same network as the remote application may be able to utilize a timing attack to discover information about the remote secret. In extreme circumstances this could result in the attacker determining the secret and uploading changed classes, thereby achieving remote code execution in the remote application.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); DevTools remote secret comparison. Versions that are no longer supported are also affected per vendor advisory.

Spring Boot's Cassandra auto-configuration does not perform hostname verification when establishing an SSL connection to Cassandra.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); Cassandra SSL auto-configuration. Versions that are no longer supported are also affected per vendor advisory.

Values produced by ${random.value} are not suitable for use as secrets. ${random.uuid} is not affected. ${random.int} and ${random.long} should never be used for secrets as they are numeric values with a predictable range.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); random value property source / weak PRNG for secrets. Versions that are no longer supported are also affected per vendor advisory.

In certain circumstances, Spring Boot's default web security is ineffective allowing unauthorized access to all endpoints. For an application to be vulnerable, it must: be a servlet-based web application; have no Spring Security configuration of its own and rely on the default web security filter chain; depend on spring-boot-actuator-autoconfigure; not depend on spring-boot-health. If any of the above does not apply, the application is not vulnerable.

Affected: Spring Boot 4.0.0–4.0.5; upgrade to 4.0.6 or later per vendor advisory.

When an application is configured to use ApplicationPidFileWriter, a local attacker with write access to the PID file's location can corrupt one file on the host each time the application is started.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); PID file / symlink behavior (ApplicationPidFileWriter). Versions that are no longer supported are also affected per vendor advisory.

A local attacker on the same host as the application may be able to take control of the directory used by ApplicationTemp. When server.servlet.session.persistent is set to true and the attack persists across application restarts, this may allow the attacker to read session information and hijack authenticated users or deploy a gadget chain and execute code as the application's user.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); predictable temp directory / ApplicationTemp ownership verification. Versions that are no longer supported are also affected per vendor advisory.

Malicious PATCH requests submitted to servers using Spring Data REST backed HTTP resources can use specially crafted JSON data to run arbitrary Java code.

Spring Boot's Mail auto-configuration does not enable hostname verification. Applications that set the relevant JavaMail property, such as spring.mail.properties.mail.smtp.ssl.checkserveridentity=true, are not affected.

Affected versions: Spring Boot 4.0.0 through 4.0.6; 3.5.0 through 3.5.14; 3.4.0 through 3.4.16.

Values produced by ${random.value} are not suitable for use as secrets. ${random.uuid} is not affected. ${random.int} and ${random.long} should never be used for secrets as they are numeric values with a predictable range.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); random value property source / weak PRNG for secrets. Versions that are no longer supported are also affected per vendor advisory.

Spring Boot applications with Actuator can be vulnerable to an "Authentication Bypass" vulnerability when an application endpoint that requires authentication is declared under a specific path, already configured for a Health Group additional path. This issue affects Spring Boot: from 4.0 before 4.0.3, from 3.5 before 3.5.11, from 3.4 before 3.4.15. This CVE is similar but not equivalent to CVE-2026-22733, as the conditions for exploit and vulnerable versions are different.

An attacker on the same network as the remote application may be able to utilize a timing attack to discover information about the remote secret. In extreme circumstances this could result in the attacker determining the secret and uploading changed classes, thereby achieving remote code execution in the remote application.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); DevTools remote secret comparison. Versions that are no longer supported are also affected per vendor advisory.

A local attacker on the same host as the application may be able to take control of the directory used by ApplicationTemp. When server.servlet.session.persistent is set to true and the attack persists across application restarts, this may allow the attacker to read session information and hijack authenticated users or deploy a gadget chain and execute code as the application's user.

Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); predictable temp directory / ApplicationTemp ownership verification. Versions that are no longer supported are also affected per vendor advisory.

When configured to use an SSL bundle, Spring Boot's Elasticsearch auto-configuration does not perform hostname verification when connecting to the Elasticsearch server.

Affected: Spring Boot 4.0.0–4.0.5; upgrade to 4.0.6 or later per vendor advisory.

Spring Boot supports an embedded launch script that can be used to easily run the application as a systemd or init.d linux service. The script included with Spring Boot 1.5.9 and earlier and 2.0.0.M1 through 2.0.0.M7 is susceptible to a symlink attack which allows the "runuser" to overwrite and take ownership of any file on the same system. In order to instigate the attack, the application must be installed as a service and the "runuser" requires shell access to the server. Spring Boot application that are not installed as a service, or are not using the embedded launch script are not susceptible.