What’s Vulnerable › Vulnerabilities

CVE-2026-40976

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-27 · updated 2026-07-24
• Weakness: CWE-862

Description

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.

Affected products

• Spring Boot: from 4.0.0 before 4.0.6 — fixed in 4.0.6
• Spring Boot: from 4.0.0 before 4.0.6 — fixed in 4.0.6

How to fix

Upgrade to a fixed version: Spring Boot 4.0.6; Spring Boot 4.0.6. Check the vendor advisory for mitigations.

References

• https://spring.io/security/cve-2026-40976
• https://access.redhat.com/security/cve/CVE-2026-40976
• https://bugzilla.redhat.com/show_bug.cgi?id=2463322
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40976.json

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