CVE-2026-40992: Spring Framework Spring Boot's Mail Auto-Configuration Does Vulnerability

MODERATE
Advisory Identifier: GHSA-9wxp-w4px-32vh
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CVSS 5.0
CWE-295
Published
Advisory Summary

CVE-2026-40992 is a MODERATE (CVSS 5.0) spring boot's mail auto-configuration does vulnerability (CWE-295: Improper Certificate Validation) affecting Spring Framework libraries in the Maven ecosystem. The issue involves spring boot's mail auto-configuration does not enable ssl hostname verification. Remediation is available by upgrading affected packages to version 4.0.7, 3.5.15.

CVE-2026-40992 at a Glance

CVE Identifier CVE-2026-40992
GHSA Identifier GHSA-9wxp-w4px-32vh
Severity MODERATE
CVSS v3.1 Base Score 5.0
CWE Classification CWE-295: Improper Certificate Validation
Affected Product Spring Framework
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L).

Attack Vector Adjacent (AV:A)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-40992

To remediate this vulnerability, upgrade all affected Spring Framework dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.springframework.boot:spring-boot-starter-mail fixed: 4.0.7 
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
    <version>4.0.7</version>
</dependency>
org.springframework.boot:spring-boot-starter-mail fixed: 3.5.15 
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
    <version>3.5.15</version>
</dependency>
org.springframework.boot:spring-boot-starter-mail fixed: Latest secure release 
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
    <version>Latest secure release</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.springframework.boot

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-40992, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.springframework.boot

Analyze the terminal output to locate any version of Spring Framework in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.0.7), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.springframework.boot command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-295: Improper Certificate Validation, where the product does not validate, or incorrectly validates, a certificate. In Spring Framework, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-40992 Affected Spring Framework Versions

3 component(s)
Fixed Versions:
4.0.73.5.15
Product / Package Ecosystem Affected Versions Fixed Version
org.springframework.boot:spring-boot-starter-mail
maven/org.springframework.boot/spring-boot-starter-mail
Maven
≥ 4.0.0
< 4.0.7
4.0.7
org.springframework.boot:spring-boot-starter-mail
maven/org.springframework.boot/spring-boot-starter-mail
Maven
≥ 3.5.0
< 3.5.15
3.5.15
org.springframework.boot:spring-boot-starter-mail
maven/org.springframework.boot/spring-boot-starter-mail
Maven
≥ 3.4.0
≤ 3.4.16

References

NVD — CVE-2026-40992 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40992
Spring Framework Source Repository REPOSITORY
https://github.com/spring-projects/spring-boot
Spring Framework Security Information SECURITY
https://spring.io/security/cve-2026-40992

Frequently Asked Questions

What is CVE-2026-40992?
CVE-2026-40992 is a security vulnerability in Spring Framework involving Spring Boot's Mail Auto-Configuration Does Not Enable SSL Hostname Verification under CWE-295: Improper Certificate Validation.
Which Spring Framework versions are affected?
Affected versions include releases prior to 4.0.7, 3.5.15 across affected packages: org.springframework.boot:spring-boot-starter-mail.
What version fixes CVE-2026-40992?
Upgrading to 4.0.7, 3.5.15 (or the latest patched release for your respective branch) resolves the vulnerability.
Is spring-boot-starter-mail affected?
Yes, org.springframework.boot:spring-boot-starter-mail is affected in releases prior to 4.0.7, 3.5.15, Latest secure release. Upgrade your dependency to 4.0.7, 3.5.15, Latest secure release or later.
What is the CVSS score of CVE-2026-40992?
CVE-2026-40992 has a CVSS v3.1 base score of 5.0 (MODERATE) with vector string CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2026-40992?
CVE-2026-40992 is classified under CWE-295: Improper Certificate Validation (The product does not validate, or incorrectly validates, a certificate.).
How can I check Maven dependencies for CVE-2026-40992?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.springframework.boot'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9wxp-w4px-32vh",
  "modified" : "2026-08-18T20:13:38Z",
  "published" : "2026-06-11T09:31:55Z",
  "aliases" : [ "CVE-2026-40992" ],
  "summary" : "Spring Boot's Mail Auto-Configuration Does Not Enable SSL Hostname Verification",
  "details" : "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.\n\nAffected versions:\nSpring Boot 4.0.0 through 4.0.6; 3.5.0 through 3.5.14; 3.4.0 through 3.4.16.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.boot:spring-boot-starter-mail"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.0.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.0.6"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.boot:spring-boot-starter-mail"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.5.0"
      }, {
        "fixed" : "3.5.15"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.5.14"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.springframework.boot:spring-boot-starter-mail"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.4.0"
      }, {
        "last_affected" : "3.4.16"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40992"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/spring-projects/spring-boot"
  }, {
    "type" : "WEB",
    "url" : "https://spring.io/security/cve-2026-40992"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-295" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-18T20:13:38Z",
    "nvd_published_at" : "2026-06-11T07:16:27Z"
  }
}