PatchSiren cyber security CVE debrief

CVE-2026-47838 VMware CVE debrief

CVE-2026-47838 is a medium-severity vulnerability (CVSS Score: 6.8) affecting Spring Security versions 5.7.0 through 5.7.24, 5.8.0 through 5.8.26, 6.3.0 through 6.3.17, 6.4.0 through 6.4.17, and 6.5.0 through 6.5.10. The vulnerability is caused by the SubjectDnX509PrincipalExtractor not correctly handling certain malformed X.509 certificate CN values, which can lead to reading the wrong value for the username. In a carefully crafted certificate, this can lead to an attacker impersonating another user.

Vendor: VMware
Product: Spring Security
CVSS: MEDIUM 6.8
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-10
Original CVE updated: 2026-06-10
Advisory published: 2026-06-10
Advisory updated: 2026-06-10

Who should care

Users of affected Spring Security versions should be aware of this vulnerability and take steps to mitigate it.

Technical summary

The SubjectDnX509PrincipalExtractor does not correctly handle certain malformed X.509 certificate CN values, which can lead to reading the wrong value for the username.

Defensive priority

medium

Recommended defensive actions

Upgrade to a non-vulnerable version of Spring Security.
Implement additional authentication and authorization measures to prevent impersonation attacks.

Evidence notes

The CVE record and NVD detail pages provide additional information about this vulnerability.

Official resources

CVE-2026-47838 was published on 2026-06-10T00:16:54.897Z and modified on 2026-06-10T19:24:04.320Z.