Medium severity · published Jun 11, 2026
CVE-2026-40992
Mail Auto-Configuration Does Not Enable SSL Hostname Verification
5.0
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Adjacent
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SB
Spring Boot · Spring
4.0.0 before 4.0.6.1; 3.5.0 before 3.5.14.1; 3.4.0 before 3.4.17 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40992
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40992
Vendor Advisory
https://spring.io/security/cve-2026-40992
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