Spring Security Vulnerable to Unauthorized User Impersonation when Using X.509 Client Certificates
In Spring Security Web, `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. `SubjectDnX509PrincipalExtractor` is deprecated by this CVE and replaced with `SubjectX500PrincipalExtractor`. As part of updating, you should also migrate to `SubjectX500PrincipalExtractor`. Affected versions: Spring Security Enterprise 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. OSS 6.5.0 through 6.5.10.
describes (1)
Related CVEs.
| ID | severity | exploitable |
|---|---|---|
| CVE-2026-47838US | high | — |
references
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