CVE-2026-40971 VMware CVE debrief

Who should care

Security teams and developers using Spring Boot with RabbitMQ and SSL bundle configurations should prioritize patching to prevent potential man-in-the-middle attacks. This includes reviewing and updating SSL bundle configurations to ensure proper hostname verification. Additionally, monitoring for suspicious RabbitMQ connection attempts and implementing additional security measures such as network segmentation and access controls are recommended.

Technical summary

The vulnerability arises from the lack of hostname verification in Spring Boot's RabbitMQ auto-configuration when using an SSL bundle. This oversight could allow for man-in-the-middle attacks, potentially leading to data breaches or unauthorized access. The CVSS score for this vulnerability is 5, indicating a medium severity level. Affected versions include Spring Boot 4.0.0–4.0.5 and 3.5.0–3.5.13; fixes are available in 4.0.6 and 3.5.14. To mitigate this vulnerability, it is essential to apply patches immediately for affected Spring Boot versions and review SSL bundle configurations.

Defensive priority

Apply patches immediately for Spring Boot versions 4.0.0–4.0.5 and 3.5.0–3.5.13. Implement compensating controls such as network monitoring and intrusion detection to detect potential exploitation attempts. Review and update SSL bundle configurations to ensure proper hostname verification. Monitor for suspicious RabbitMQ connection attempts and implement additional security measures such as network segmentation and access controls. Track exceptions, retest remediated assets, and close the item only after evidence is documented. Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up. Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. Check relevant monitoring, detection, and logs for exposed assets that need extra review. Consider implementing source tracking to monitor for potential exploitation attempts.

Recommended defensive actions

• Apply patches for affected Spring Boot versions
• Review and update SSL bundle configurations
• Monitor for suspicious RabbitMQ connection attempts
• Implement additional security measures such as network segmentation and access controls
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

Evidence for this vulnerability comes from the NVD and vendor advisory sources. The CVE record and NVD detail provide information on the affected versions and patches. The vendor advisory offers mitigation strategies and confirms the vulnerability. Defenders should verify the SSL bundle configuration and RabbitMQ broker connection settings to ensure hostname verification is properly implemented.

Official resources