CVE-2026-4282: Keycloak Privilege Escalation Vulnerability

HIGH
Advisory Identifier: GHSA-hj93-h7pg-fh6v
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CVSS 7.4
CWE-653
Published
Advisory Summary

CVE-2026-4282 is a HIGH (CVSS 7.4) privilege escalation vulnerability (CWE-653: Improper Isolation or Compartmentalization) affecting Keycloak libraries in the Maven ecosystem. The issue involves privilege escalation via forged authorization codes due to singleuseobjectprovider isolation flaw. Remediation is available by upgrading affected packages to version 26.5.7.

CVE-2026-4282 at a Glance

CVE Identifier CVE-2026-4282
GHSA Identifier GHSA-hj93-h7pg-fh6v
Severity HIGH
CVSS v3.1 Base Score 7.4
CWE Classification CWE-653: Improper Isolation or Compartmentalization
Affected Product Keycloak
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.4

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

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

How to Fix CVE-2026-4282

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: 26.5.7 
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>26.5.7</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-2026-4282, 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 26.5.7), 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-653: Improper Isolation or Compartmentalization, where the product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions. 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 Keycloak. The SingleUseObjectProvider, a global key-value store, lacks proper type and namespace isolation. This vulnerability allows an unauthenticated attacker to forge authorization codes. Successful exploitation can lead to the creation of admin-capable access tokens, resulting in privilege escalation.

CVE-2026-4282 Affected Keycloak Versions

1 component(s)
Fixed Versions:
26.5.7
Product / Package Ecosystem Affected Versions Fixed Version
org.keycloak:keycloak-services
maven/org.keycloak/keycloak-services
Maven
< 26.5.7
26.5.7

References

NVD — CVE-2026-4282 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4282
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak/issues/47719
Security Fix Commit FIX COMMIT
https://github.com/keycloak/keycloak/commit/9046f201125a6fd6be9c116b99d348509d99d4a5
access.redhat.com/errata/rhsa-2026:64... WEB
https://access.redhat.com/errata/RHSA-2026:6475
access.redhat.com/errata/rhsa-2026:64... WEB
https://access.redhat.com/errata/RHSA-2026:6476
access.redhat.com/errata/rhsa-2026:64... WEB
https://access.redhat.com/errata/RHSA-2026:6477
access.redhat.com/errata/rhsa-2026:64... WEB
https://access.redhat.com/errata/RHSA-2026:6478
Keycloak Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-4282
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2448061
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak

Frequently Asked Questions

What is CVE-2026-4282?
CVE-2026-4282 is a security vulnerability in Keycloak involving Privilege escalation via forged authorization codes due to SingleUseObjectProvider isolation flaw under CWE-653: Improper Isolation or Compartmentalization.
Which Keycloak versions are affected?
Affected versions include releases prior to 26.5.7 across affected packages: org.keycloak:keycloak-services.
What version fixes CVE-2026-4282?
Upgrading to 26.5.7 (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 26.5.7. Upgrade your dependency to 26.5.7 or later.
What is the CVSS score of CVE-2026-4282?
CVE-2026-4282 has a CVSS v3.1 base score of 7.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-4282?
CVE-2026-4282 is classified under CWE-653: Improper Isolation or Compartmentalization (The product does not properly compartmentalize or isolate functionality, processes, or resources that require different privilege levels, rights, or permissions.).
How can I check Maven dependencies for CVE-2026-4282?
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-hj93-h7pg-fh6v",
  "modified" : "2026-04-04T05:56:42Z",
  "published" : "2026-04-02T15:31:39Z",
  "aliases" : [ "CVE-2026-4282" ],
  "summary" : "Keycloak: Privilege escalation via forged authorization codes due to SingleUseObjectProvider isolation flaw",
  "details" : "A flaw was found in Keycloak. The SingleUseObjectProvider, a global key-value store, lacks proper type and namespace isolation. This vulnerability allows an unauthenticated attacker to forge authorization codes. Successful exploitation can lead to the creation of admin-capable access tokens, resulting in privilege escalation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.5.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4282"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/issues/47719"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/commit/9046f201125a6fd6be9c116b99d348509d99d4a5"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6475"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6476"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6477"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6478"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-4282"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2448061"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/keycloak/keycloak"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-653" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-04T05:56:42Z",
    "nvd_published_at" : "2026-04-02T13:16:26Z"
  }
}