CVE-2026-37981Network attack vector

Authenticated PII disclosure via unchecked user lookup

Published May 19, 2026 · Updated May 19, 2026

Broken access control in Red Hat build of Keycloak before 26.4.12 allows remote authenticated users to read realm-user PII. ResourceService.user resolves an arbitrary username or email and returned the resulting profile without checking that it belongs to the caller or a permission requester. Exploitation requires authentication and ownership of at least one UMA resource, and exposes unrelated users' IDs, names, usernames, emails, and status.

CVSS severity4.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Broken access control in Red Hat build of Keycloak before 26.4.12 allows remote authenticated users to read realm-user PII. ResourceService.user resolves an arbitrary username or email and returned the resulting profile without checking that it belongs to the caller or a permission requester. Exploitation requires authentication and ownership of at least one UMA resource, and exposes unrelated users' IDs, names, usernames, emails, and status.

The record

CVE
CVE-2026-37981
Published
May 19, 2026
Updated
May 19, 2026
Vendor
389 Directory Server
Product
Red Hat build of Keycloak
Classifications
CWE-1220, T1213, T1087
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

389 Directory Server · Red Hat build of KeycloakAffected versions are unavailable in this record.

Published CVSS scores

4.3GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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-1220Insufficient Granularity of Access Control
T1213Data from Information Repositories
T1087Account Discovery

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo