Spring BootFramework / library · VMware
CVE-2026-40971
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWhen configured to use an SSL bundle, Spring Boot's RabbitMQ auto-configuration does not perform hostname verification when connecting to the RabbitMQ broker. Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14) per vendor advisory.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceSpring Boot's RabbitMQ auto-configuration skips hostname verification when SSL bundles are used, allowing man-in-the-middle attackers to intercept encrypted connections by presenting a valid certificate for an unrelated hostname.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Spring BootFramework / library
>= 3.5.0, < 3.5.14>= 4.0.0, < 4.0.6CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the Spring Boot versionInspect your project's build file (pom.xml or build.gradle) or the MANIFEST.MF inside the spring-boot-*.jar to find the exact version of spring-boot-starter parent or the spring-boot libraries.Affected if The version falls within 3.5.0 to 3.5.13, or 4.0.0 to 4.0.5.
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Locate RabbitMQ configurationSearch your application.properties or application.yml files for any rabbitmq configuration section, typically under spring.rabbitmq.Affected if RabbitMQ is configured in the application.
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Verify SSL is enabled via SSL bundleLook for spring.rabbitmq.ssl.enabled=true and spring.rabbitmq.ssl.bundle= in your configuration files. The ssl.bundle property indicates usage of SSL bundle configuration.Affected if spring.rabbitmq.ssl.enabled is true AND spring.rabbitmq.ssl.bundle is set to a non-empty value.
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Check hostname verification settingInspect the SSL bundle configuration (in application.yml under spring.rabbitmq.ssl.bundles) and check if key store and trust store are configured. Look for any explicit hostname-verification setting such as verify-hostname=true or the absence of such configuration.Affected if Hostname verification is not explicitly set to true, or the SSL bundle configuration lacks proper hostname verification settings.
You are affected if you use Spring Boot version 3.5.0-3.5.13 or 4.0.0-4.0.5 with RabbitMQ SSL enabled via an SSL bundle where hostname verification is not explicitly enforced.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped3.5.144.0.6
Upgrade Spring Boot to version 4.0.6 or 3.5.14 which includes the fix, or verify SSL hostname verification is enforced at the broker configuration level.
Spring Boot 3.5.14 (for 3.5.x users) or 4.0.6 (for 4.0.x users)
- Identify your current Spring Boot version (3.5.x or 4.0.x) from your pom.xml or build.gradle
- If using Spring Boot 3.5.x, upgrade to version 3.5.14 or later
- If using Spring Boot 4.0.x, upgrade to version 4.0.6 or later
- Update the spring-boot-starter-parent version in your pom.xml or update the version property in build.gradle
- Run your build to verify the upgrade completes successfully
- Test your RabbitMQ SSL connections to ensure the hostname verification is now properly enforced
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Spring Boot
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40971 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-40971 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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