---
title: "CVE-2026-40976: Spring Boot's default security filter chain has no authorization rule with Actuator but without Health"
url: https://erroneo.us/security/cve/CVE-2026-40976/
description: "CVE-2026-40976 (org.springframework.boot:spring-boot (Maven)): In certain circumstances, Spring Boot's default web security is ineffective allowing…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-27
date_modified: 2026-07-15
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-40976"
kev: false
cvss: 9.1
epss: 0.00538
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-40976: Spring Boot's default security filter chain has no authorization rule with Actuator but without Health

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.5% , percentile 44: FIRST’s model estimates a 0.5% chance of exploitation activity in the next 30 days, higher than 44% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.springframework.boot:spring-boot (Maven) >= 4.0.0, < 4.0.6, fixed in 4.0.6 . Check your lockfile, including transitive dependencies.

## What it is

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 packages

- Maven `org.springframework.boot:spring-boot` >= 4.0.0, < 4.0.6 → fixed: 4.0.6

## Affected products (CVE record)

- Spring Spring Boot: 4.0.0 < 4.0.6

## Severity

- vmware CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- redhat-SADP CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.54% probability of exploitation activity in the next 30 days; percentile 44.

## Sources

- [GitHub Advisory GHSA-8v8j-3hxp-93wr](https://github.com/advisories/GHSA-8v8j-3hxp-93wr)
- [CVE.org record CVE-2026-40976](https://www.cve.org/CVERecord?id=CVE-2026-40976)
- [NVD entry CVE-2026-40976](https://nvd.nist.gov/vuln/detail/CVE-2026-40976)
- [spring.io](https://spring.io/security/cve-2026-40976)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-40976)
- [RHBZ#2463322](https://bugzilla.redhat.com/show_bug.cgi?id=2463322)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40976.json)

---
Source page: https://erroneo.us/security/cve/CVE-2026-40976/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt