Auth bypass in Spring Security
CVE-2026-47838
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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (8.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 8.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Spring Security — versions 5.7.0, 5.8.0, 6.3.0
- VMware Spring Security
Weakness classification (CWE)
References
- spring.io/security/cve-2026-47838 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-47838?
- CVE-2026-47838 is a medium-severity vulnerability in Spring Security, classified under Improper Authentication. CVSS score: 6.8/10. Published 2026-06-10.
- How severe is CVE-2026-47838?
- Medium severity. CVSS v3 base score is 6.8 out of 10.