CVE-2026-40977

Spring Boot versions 4.0.0–4.0.5 have ineffective default web security, allowing unauthorized access to all endpoints. The vulnerability affects servlet-based applications without custom Spring Security configuration, using spring-boot-actuator-autoconfigure and not depending on spring-boot-health.

Vulnerability in Spring Boot where ArtemisEmbeddedConfigurationFactory uses a fixed, predictable path for the Artemis broker data directory. A local attacker can create a symlink before application start.

In Spring Boot, a vulnerability was found in the mail auto-configuration that does not enable hostname verification. Applications that explicitly set the JavaMail property (e.g., spring.mail.properties.mail.smtp.ssl.checkserveridentity=true) are not affected. Affected versions are Spring Boot 4.0.0-4.0.6, 3.5.0-3.5.14, and 3.4.0-3.4.16.

In Spring Boot, values produced by ${random.value} are not suitable for use as secrets. ${random.uuid} is not affected, but ${random.int} and ${random.long} have a predictable range. Affected versions: 4.0.0–4.0.5, 3.5.0–3.5.13, 3.4.0–3.4.15, 3.3.0–3.3.18, 2.7.0–2.7.32.

Spring Boot's Cassandra auto-configuration does not perform hostname verification when establishing an SSL connection to Cassandra. This affects multiple Spring Boot versions including 4.0.0–4.0.5, 3.5.0–3.5.13, 3.4.0–3.4.15, 3.3.0–3.3.18, and 2.7.0–2.7.32.

Spring Boot versions 4.0.0-4.0.5, 3.5.0-3.5.13, 3.4.0-3.4.15, 3.3.0-3.3.18, 2.7.0-2.7.32 have a vulnerability due to a predictable temp directory (ApplicationTemp). A local attacker can take control of this directory, and with persistent sessions enabled, can read sessions, hijack users, or execute code.

An attacker on the same network as the remote application may use a timing attack to leak information about the remote secret. In extreme cases, this could allow the attacker to determine the secret and upload modified classes, achieving remote code execution.

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 versions: Spring Boot 4.0.0–4.0.5 (fixed in 4.0.6), 3.5.0–3.5.13 (fixed in 3.5.14).