How to Fix CVE-2026-40972: Spring Boot (Bundle Sibling)
By Sai Kiran Pandrala
Last verified: 2026-05-25
CVE-2026-40972 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 7.5 - High |
|---|---|
| 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-208: CWE-208: Observable Timing Discrepancy |
What's different about CVE-2026-40972?
An attacker on the same network as the remote application may be able to utilize a timing attack to discover information about the remote secret. In extreme circumstances this could result in the attacker determining the secret and uploading changed classes, thereby achieving remote code execution in the remote application.
Affected: Spring Boot 4.0.0–4.0.5 (fix 4.0.6), 3.5.0–3.5.13 (fix 3.5.14), 3.4.0–3.4.15 (fix 3.4.16), 3.3.0–3.3.18 (fix 3.3.19), 2.7.0–2.7.32 (fix 2.7.33); DevTools remote secret comparison. Versions that are no longer supported are also affected 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-2026-40972
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-2026-40972 fixed by the same patch as CVE-2026-40970?
Yes. CVE-2026-40972 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-2026-40972?
The CVSS base score is 7.5 (High).
Is it being exploited?
It is not currently listed in CISA KEV.
References
- Official vendor advisory: https://spring.io/security/cve-2026-40972
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-40972
- 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.*