Vulnerability · Published Jun 11, 2026 · Assigned by vmware
CVE-2026-40992Mail Auto-Configuration Does Not Enable SSL Hostname Verification
Medium 5.0
In plain English
A medium-severity improper certificate validation in Spring Boot from Spring. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Spring Boot's 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.springframework.boot:spring-boot-starter-mail | 4.0.7 | GHSA-9wxp-w4px-32vh |
| Maven | org.springframework.boot:spring-boot-starter-mail | 3.5.15 | GHSA-9wxp-w4px-32vh |
| Maven | org.springframework.boot:spring-boot-starter-mail | no fix listed | GHSA-9wxp-w4px-32vh |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Spring | Spring Boot | 4.0.0 – before 4.0.6.13.5.0 – before 3.5.14.13.4.0 – before 3.4.17 |
Weakness: CWE-295 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L