Improper Certificate Validation in Spring Boot - CVE-2026-40992
Published: June 11, 2026
Vulnerability identifier: #VU134322
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-40992
CWE-ID: CWE-295
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Spring
Affected software:
Spring Boot
Spring Boot
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information, modify data, or cause a denial of service.
The vulnerability exists due to improper certificate validation in mail auto-configuration when establishing SSL/TLS connections to a mail server. A remote attacker can present a crafted server certificate to disclose sensitive information, modify data, or cause a denial of service.
Applications that explicitly enable the JavaMail server identity check property are not affected.
How to mitigate CVE-2026-40992
Install security update from vendor's website.