How to Fix CVE-2026-40971: Spring Boot (Bundle Sibling)
By Sai Kiran Pandrala
Last verified: 2026-05-25
CVE-2026-40971 is a sibling vulnerability in the same vendor advisory as CVE-2026-40970. Applying the patched build named in the primary write-up closes this CVE as well.
| Severity | CVSS 5 - Medium |
|---|---|
| Actively exploited? | Not currently in CISA KEV |
| Affected | Same as the bundle - see CVE-2026-40970 |
| Fixed in | Same patched build as CVE-2026-40970 (See vendor advisory) |
| Type (CWE) | CWE-295: CWE-295: Improper Certificate Validation |
What's different about CVE-2026-40971?
When 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.
The technical impact and remediation are identical to the primary CVE in the bundle. The same vendor patch closes both.
How to fix CVE-2026-40971
Apply the patched build per the primary write-up: How to Fix CVE-2026-40970.
The patch installation procedure, verification commands, and interim mitigations are documented there. Reusing one runbook keeps the rollout consistent across the bundle.
Frequently asked questions
Is CVE-2026-40971 fixed by the same patch as CVE-2026-40970?
Yes. CVE-2026-40971 ships in the same vendor advisory as CVE-2026-40970. Applying the patched build named in the primary write-up closes both.
What is the CVSS score for CVE-2026-40971?
The CVSS base score is 5 (Medium).
Is it being exploited?
It is not currently listed in CISA KEV.
References
- Official vendor advisory: https://spring.io/security/cve-2026-40971
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-40971
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary write-up: How to Fix CVE-2026-40970
*Part of the Spring Boot bundle. Full procedure at CVE-2026-40970.*