CVE-2026-9088: Keycloak Information Disclosure Due To User Vulnerability

LOW
Advisory Identifier: GHSA-6g26-7cx5-mrrg
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CVSS 2.7
CWE-1220
Published
Advisory Summary

CVE-2026-9088 is a LOW (CVSS 2.7) information disclosure due to user vulnerability (CWE-1220: Insufficient Granularity of Access Control) affecting Keycloak libraries in the Maven ecosystem. The issue involves information disclosure due to user profile permission bypass. Remediation is available by upgrading affected packages to version 26.7.0.

CVE-2026-9088 at a Glance

CVE Identifier CVE-2026-9088
GHSA Identifier GHSA-6g26-7cx5-mrrg
Severity LOW
CVSS v3.1 Base Score 2.7
CWE Classification CWE-1220: Insufficient Granularity of Access Control
Affected Product Keycloak
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 2.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-9088

To remediate this vulnerability, upgrade all affected Keycloak dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.keycloak:keycloak-services fixed: 26.7.0 
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>26.7.0</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.keycloak

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-9088, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.keycloak

Analyze the terminal output to locate any version of Keycloak in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 26.7.0), your application is affected.

Note: The mvn dependency:tree -Dincludes=org.keycloak command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1220: Insufficient Granularity of Access Control, where the product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. however, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets. In Keycloak, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A flaw was found in org.keycloak.services. An administrator with delegated access to read group memberships and users can bypass user profile permissions by accessing the group members endpoint. This allows the administrator to view user attributes that are explicitly configured to be denied, leading to information disclosure.

CVE-2026-9088 Affected Keycloak Versions

1 component(s)
Fixed Versions:
26.7.0
Product / Package Ecosystem Affected Versions Fixed Version
org.keycloak:keycloak-services
maven/org.keycloak/keycloak-services
Maven
< 26.7.0
26.7.0

References

NVD — CVE-2026-9088 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9088
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak/issues/49174
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak/pull/49391
Security Fix Commit FIX COMMIT
https://github.com/keycloak/keycloak/commit/bf0df40a91a05e550891dcdae2d922b556db7e7b
access.redhat.com/errata/rhsa-2026:25... WEB
https://access.redhat.com/errata/RHSA-2026:25097
access.redhat.com/errata/rhsa-2026:25... WEB
https://access.redhat.com/errata/RHSA-2026:25098
access.redhat.com/errata/rhsa-2026:30... WEB
https://access.redhat.com/errata/RHSA-2026:30049
access.redhat.com/errata/rhsa-2026:30... WEB
https://access.redhat.com/errata/RHSA-2026:30050
Keycloak Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-9088
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2480179
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak

Frequently Asked Questions

What is CVE-2026-9088?
CVE-2026-9088 is a security vulnerability in Keycloak involving Information disclosure due to user profile permission bypass under CWE-1220: Insufficient Granularity of Access Control.
Which Keycloak versions are affected?
Affected versions include releases prior to 26.7.0 across affected packages: org.keycloak:keycloak-services.
What version fixes CVE-2026-9088?
Upgrading to 26.7.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is keycloak-services affected?
Yes, org.keycloak:keycloak-services is affected in releases prior to 26.7.0. Upgrade your dependency to 26.7.0 or later.
What is the CVSS score of CVE-2026-9088?
CVE-2026-9088 has a CVSS v3.1 base score of 2.7 (LOW) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-9088?
CVE-2026-9088 is classified under CWE-1220: Insufficient Granularity of Access Control (The product implements access controls via a policy or other feature with the intention to disable or restrict accesses (reads and/or writes) to assets in a system from untrusted agents. However, implemented access controls lack required granularity, which renders the control policy too broad because it allows accesses from unauthorized agents to the security-sensitive assets.).
How can I check Maven dependencies for CVE-2026-9088?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.keycloak'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6g26-7cx5-mrrg",
  "modified" : "2026-07-16T19:26:10Z",
  "published" : "2026-06-05T09:33:46Z",
  "aliases" : [ "CVE-2026-9088" ],
  "summary" : "Keycloak: Information disclosure due to user profile permission bypass",
  "details" : "A flaw was found in org.keycloak.services. An administrator with delegated access to read group memberships and users can bypass user profile permissions by accessing the group members endpoint. This allows the administrator to view user attributes that are explicitly configured to be denied, leading to information disclosure.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.7.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-9088"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/issues/49174"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/pull/49391"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/commit/bf0df40a91a05e550891dcdae2d922b556db7e7b"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:25097"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:25098"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:30049"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:30050"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-9088"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2480179"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/keycloak/keycloak"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1220" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-16T19:26:10Z",
    "nvd_published_at" : "2026-06-05T08:16:30Z"
  }
}