Improper Validation of Certificate with Host Mismatch Affecting org.springframework.boot:spring-boot-mail package, versions [3.4.0,3.5.15)[4.0.0-M1,4.0.7)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-JAVA-ORGSPRINGFRAMEWORKBOOT-18322496
- published27 Jul 2026
- disclosed10 Jun 2026
- creditUnknown
Introduced: 10 Jun 2026
CVE-2026-40992 (opens in a new tab)How to fix?
Upgrade org.springframework.boot:spring-boot-mail to version 3.5.15, 4.0.7 or higher.
Overview
org.springframework.boot:spring-boot-mail is a
Affected versions of this package are vulnerable to Improper Validation of Certificate with Host Mismatch. via missing hostname verification in the auto-configuration. An attacker can impersonate a trusted mail server and intercept or manipulate SMTP communications because hostname verification is not enabled by default when establishing TLS-protected mail connections.
Note: Applications that explicitly enable hostname verification, for example by setting spring.mail.properties.mail.smtp.ssl.checkserveridentity=true, are not affected.