CVE-2026-40992

Spring Boots Mail auto-configuration does not enable hostname verification. Applications that set the relevant JavaMail property, such as spring.mail.properties.mail.smtp.ssl.checkserveridentity=true, are not affected.

Affected versions: Spring Boot 4.0.0 through 4.0.6; 3.5.0 through 3.5.14; 3.4.0 through 3.4.16.

Weakness

The product does not validate, or incorrectly validates, a certificate.

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/459.html
• https://cwe.mitre.org/data/definitions/475.html

References

• https://spring.io/security/cve-2026-40992