What is CVE-2026-40976?

CVE-2026-40976 is a critical-severity vulnerability in Spring Boot, classified under Missing Authorization. CVSS score: 9.1/10. Published 2026-04-28.

How severe is CVE-2026-40976?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Auth bypass in Spring Boot

CVE-2026-40976

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.

Vulnerability class: Broken Access Control

EPSS: 0.005 (40.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Spring Boot — versions 4.0.0
Vmware Spring_boot

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40976?: CVE-2026-40976 is a critical-severity vulnerability in Spring Boot, classified under Missing Authorization. CVSS score: 9.1/10. Published 2026-04-28.
How severe is CVE-2026-40976?: Critical severity. CVSS v3 base score is 9.1 out of 10.