How severe is CVE-2026-40992?

CVE-2026-40992 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-40992 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40992?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40992 have an EU (EUVD) identifier?

Yes. CVE-2026-40992 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36203.

When was CVE-2026-40992 published?

CVE-2026-40992 was published on 2026-06-11 and last updated on 2026-06-23.

CVE-2026-40992

CVE-2026-40992 is a medium-severity vulnerability with a CVSS 3.x base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Medium (CVSS 3.x base score 5.0)
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-36203
Weakness: CWE-295
Published: 2026-06-11
Last modified: 2026-06-23

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.

Frequently asked questions

What is CVE-2026-40992?: 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.
How severe is CVE-2026-40992?: CVE-2026-40992 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-40992 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40992?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40992 have an EU (EUVD) identifier?: Yes. CVE-2026-40992 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-36203.
When was CVE-2026-40992 published?: CVE-2026-40992 was published on 2026-06-11 and last updated on 2026-06-23.

References

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

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