CVE-2026-47838

Unauthorized User Impersonation when Using X.509 Client Certificates

State: Published
Severity: 6.8 Medium
Published: Jun 9, 2026
Updated: Jun 30, 2026
Reserved: May 20, 2026

Description

SubjectDnX509PrincipalExtractor does not correctly handle 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.

Affected versions: Spring Security 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; 6.5.0 through 6.5.10.

Scores

CVSS	Score	Vector	Source
3.1	6.8 Medium	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N	vmware

Weaknesses

CWE-287 Improper Authentication

Affected Products

Product	Versions
Spring SecuritySpring	5.7.0 to before 5.7.25Affected 5.8.0 to before 5.8.27Affected 6.3.0 to before 6.3.18Affected 6.4.0 to before 6.4.18Affected 6.5.0 to before 6.5.10.2Affected

References

https://spring.io/security/cve-2026-47838

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.