CVE-2026-47838 — spring-security-web
MEDIUMCVE-2026-47838 is a medium-severity (CVSS 6.8) Improper Authentication vulnerability in org.springframework.security:spring-security-web. A fix is available for org.springframework.security:spring-security-web — see the affected versions and patch details below.
Unauthorized User Impersonation when Using X.509 Client Certificates
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-47838.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.springframework.security:spring-security-web☕org.springframework.security:spring-security-web☕org.springframework.security:spring-security-web☕org.springframework.security:spring-security-web☕org.springframework.security:spring-security-webReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.springframework.security:spring-security-web | ≥ 6.5.0&&< 6.5.11 | 6.5.11org.springframework.security:spring-security-web:6.5.11 |
| ☕Maven | org.springframework.security:spring-security-web | ≥ 6.4.0 | No fix |
| ☕Maven | org.springframework.security:spring-security-web | ≥ 6.0.0 | No fix |
| ☕Maven | org.springframework.security:spring-security-web | ≥ 5.8.0 | No fix |
| ☕Maven | org.springframework.security:spring-security-web | all versions | No fix |
Affected Products
spring securityvmwareDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.springframework.security:spring-security-web, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.springframework.security:spring-security-web to 6.5.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-47838 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-47838 in your dependencies?
Find it across Maven, including transitive dependencies.