CVE-2026-40992

Mail Auto-Configuration Does Not Enable SSL Hostname Verification

MEDIUM

CVSS Score

Published: June 11, 2026 at 05:03 AM UTC

Updated: September 4, 2026 at 06:16 PM UTC

2 products affected across 2 vendorsSpring BootSpring Boot

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Severity

MEDIUM5

Exploit prediction

EPSS 0.1%

SSVC

No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Spring Boot · VMware

95%

3.4.0 ≤ v < 3.4.173.5.0 ≤ v < 3.5.14.14.0.0 ≤ v < 4.0.6.1

Affected range stops below 3.4.17, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.5.14.1, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.0.6.1, so it looks safe — our inference, not a vendor statement

Spring Boot · Spring

60%

3.4.0 ≤ v < 3.4.173.5.0 ≤ v < 3.5.14.14.0.0 ≤ v < 4.0.6.13.4.0 3.5.0 4.0.0

Affected range stops below 3.4.17, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.5.14.1, so it looks safe — our inference, not a vendor statement

Affected range stops below 4.0.6.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

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

References (1)

Vendor Advisory

Source: cverecord

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

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5MEDIUMvmware

Attack Vector: ADJACENT_NETWORK
Complexity: HIGH
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: LOW
Integrity: LOW
Availability: LOW

Vector?

Quick Info

StatusANALYZED

CWE

CWE-295

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