4.3
MEDIUM CVSS 3.1
CVE-2026-37981
Keycloak: org.keycloak.authorization: keycloak: information disclosure via broken access control in user lookup endpoint
Description

A flaw was found in Keycloak. A broken access control vulnerability in the Account Resources user lookup endpoint allows a remote authenticated user, who owns at least one User-Managed Access (UMA) resource, to enumerate and harvest personally identifiable information (PII) for all realm users. By sending crafted requests with arbitrary usernames or email values, the endpoint returns full profile objects for unrelated users. This leads to broad profile-level information disclosure.

INFO

Published Date :

May 19, 2026, 12:16 p.m.

Last Modified :

June 3, 2026, 7:53 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-37981 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat build_of_keycloak
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 MEDIUM [email protected]
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Restrict access to the Account Resources user lookup endpoint for UMA resource owners.
  • Update Keycloak to a version that addresses this access control flaw.
  • Review and enforce granular access controls on user lookup endpoints.
  • Limit data returned by the user lookup endpoint.
  • Implement stricter validation for user identification in requests.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-37981.

URL Resource
https://access.redhat.com/errata/RHSA-2026:19596 Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:19597 Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-37981 Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2455326 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-37981 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-37981 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-37981 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-37981 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jun. 03, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:* versions from (including) 26.4 up to (excluding) 26.4.12
    Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:19596 Types: Vendor Advisory
    Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:19597 Types: Vendor Advisory
    Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-37981 Types: Vendor Advisory
    Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2455326 Types: Vendor Advisory
  • CVE Modified by [email protected]

    May. 20, 2026

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2026:19596
  • CVE Modified by [email protected]

    May. 20, 2026

    Action Type Old Value New Value
    Added Reference https://access.redhat.com/errata/RHSA-2026:19597
  • New CVE Received by [email protected]

    May. 19, 2026

    Action Type Old Value New Value
    Added Description A flaw was found in Keycloak. A broken access control vulnerability in the Account Resources user lookup endpoint allows a remote authenticated user, who owns at least one User-Managed Access (UMA) resource, to enumerate and harvest personally identifiable information (PII) for all realm users. By sending crafted requests with arbitrary usernames or email values, the endpoint returns full profile objects for unrelated users. This leads to broad profile-level information disclosure.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
    Added CWE CWE-1220
    Added Reference https://access.redhat.com/security/cve/CVE-2026-37981
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455326
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.