CVE-2026-47838Network attack vector

User impersonation via malformed certificate CN parsing

Published Jun 9, 2026 · Updated Jun 9, 2026

Improper authentication in affected Spring Security releases allows remote authenticated users to impersonate another user via X.509 certificates. SubjectDnX509PrincipalExtractor applies a regular expression to the legacy getSubjectDN().getName() string, allowing a malformed CN to be parsed as another username. Exploitation requires X.509 pre-authentication and presupposes compromise of the trusted upstream that validates the certificate.

CVSS severity6.8
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in affected Spring Security releases allows remote authenticated users to impersonate another user via X.509 certificates. SubjectDnX509PrincipalExtractor applies a regular expression to the legacy getSubjectDN().getName() string, allowing a malformed CN to be parsed as another username. Exploitation requires X.509 pre-authentication and presupposes compromise of the trusted upstream that validates the certificate.

The record

CVE
CVE-2026-47838
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Spring
Product
Spring Security
Classifications
CWE-287, T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.7.0 <5.7.25
  2. Affected versionversion=5.8.0 <5.8.27
  3. Affected versionversion=6.3.0 <6.3.18
  4. Affected versionversion=6.4.0 <6.4.18
  5. Affected versionversion=6.5.0 <6.5.11

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Spring · Spring Securityversion=5.7.0 <5.7.25; version=5.8.0 <5.8.27; version=6.3.0 <6.3.18; version=6.4.0 <6.4.18; version=6.5.0 <6.5.11

Published CVSS scores

6.8VMwareCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
8.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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