Cyber Resilience

CVE-2026-3911

Redhat Build Of Keycloak 26.4 … 26.4.11

Published
11 March 2026
Modified
07 May 2026
Patch / advisory
CVSS Score v3.1 2.7
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0033 26th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-3911 is a low-severity Exposure of Private Personal Information to an Unauthorized Actor (CWE-359) vulnerability in Redhat Build Of Keycloak. Its CVSS base score is 2.7 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Account Discovery (T1087); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A flaw was found in Keycloak. An authenticated user with the view-users role could exploit a vulnerability in the UserResource component. By accessing a specific administrative endpoint, this user could improperly retrieve user attributes that were configured to be hidden.…

more

This unauthorized information disclosure could expose sensitive user data.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
Why these techniques?

Vulnerability enables unauthorized retrieval of hidden user attributes via admin API, directly facilitating account discovery.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-4633Same product: Redhat Build Of Keycloak
CVE-2026-37981Same product: Redhat Build Of Keycloak
CVE-2026-37978Same product: Redhat Build Of Keycloak
CVE-2026-9799Same product: Redhat Build Of Keycloak
CVE-2026-9793Same product: Redhat Build Of Keycloak
CVE-2024-7318Same product: Redhat Build Of Keycloak
CVE-2026-4628Same product: Redhat Build Of Keycloak
CVE-2026-37982Same product: Redhat Build Of Keycloak
CVE-2026-9796Same product: Redhat Build Of Keycloak
CVE-2026-9792Same product: Redhat Build Of Keycloak

Affected Assets

redhat
build of keycloak
26.4, 26.4.11, all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V10.3.5
  • V10.7.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces access restrictions on the UserResource endpoint so that users holding only the view-users role cannot retrieve attributes configured as hidden.

prevent

Enforces information-flow rules that prevent disclosure of privacy-tagged user attributes to principals lacking the required clearance.

prevent

Limits the privileges granted to the view-users role so that it cannot exercise the administrative endpoint that exposes hidden attributes.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

RC.CO-04 partial match
degrades

CWE-359 does not impair RC.CO-04's ability to issue approved public recovery updates, yet any resulting PII exposure can partially undermine the outcome's overall efficacy and trust.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Masking or anonymizing personal identifiers limits the amount of private personal information that can be disclosed through application outputs or logs.

prevents

Monitoring and quarantining outbound messages that contain personal or private data directly reduces the chance that such information will be disclosed to unauthorized recipients.

prevents

The explicit prohibition on copying personally identifiable information into development and test environments directly lowers the exposure of private personal data to staff or processes that should not see it.

mitigates

Labeling, chain-of-custody, and access-control requirements limit the exposure of private personal information during any transfer method.

prevents

Mandating privacy procedures and a designated privacy officer helps ensure that private personal information is not disclosed without proper authorization or necessity.

mitigates

The agreements impose enforceable restrictions on the handling of private personal information, thereby decreasing the risk that such data will be exposed to unauthorized parties.

References