Web Security Flaw in Spring Boot Affects Servlet-Based Applications
CVE-2026-40976

9.1CRITICAL

Key Information:

Vendor

Spring

Status
Spring Boot
Vendor
CVE Published:
27 April 2026

What is CVE-2026-40976?

A security vulnerability exists in Spring Boot that could allow unauthorized access to all endpoints in certain servlet-based applications. This issue arises when applications rely on the default web security filter chain without custom security configurations. Specifically, applications dependent on spring-boot-actuator-autoconfigure, while not utilizing spring-boot-health, can be exploited. Users are advised to upgrade to Spring Boot version 4.0.6 or later to mitigate this risk.

Affected Version(s)

Spring Boot 4.0.0 < 4.0.6

References

https://spring.io/security/cve-2026-40976

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.