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Build Of KeycloakApplication · Redhat

CVE-2026-4282

HIGH · 7.4 CVSS v3.1 Published 2026-04-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
83/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Keycloak's SingleUseObjectProvider, a global key-value store used for storing transient data like authorization codes, lacks proper type and namespace isolation. This allows unauthenticated attackers to manipulate or forge authorization codes, which can then be exchanged for admin-capable access tokens, resulting in complete privilege escalation.

MitigationApply vendor patches when released; until then, implement network-level access controls and monitor for anomalous authorization code patterns. Review existing authorization code flows for signs of tampering.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Build Of KeycloakApplication
Affected:all versions= 26.2= 26.2.15= 26.4= 26.4.11

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Keycloak version
    Run 'keycloak --version' or check the server startup logs for the version number, or inspect the $KEYCLOAK_HOME/lib/lib/main directory for versioned jar files
    Affected if The installed version matches any of: 26.2, 26.2.15, 26.4, 26.4.11, or falls within 26.x series (all versions affected)
  2. Verify Keycloak is running with SingleUseObjectProvider
    Confirm Keycloak service is active and responding. The SingleUseObjectProvider is a built-in internal component used by the server for single-use token storage - if Keycloak is running, this provider is available
    Affected if Keycloak is running any affected version listed above
  3. Inspect SingleUseObjectProvider for unexpected authorization codes
    Use Keycloak admin console or API to query the single-use object store. Look for authorization codes with timestamps, issuers, or client associations that appear anomalous or were not created by legitimate authentication flows
    Affected if Any authorization codes exist in the store that were not generated by legitimate, expected authentication flows in your environment
  4. Audit recent authorization code usage for privilege escalation
    Review Keycloak authentication event logs for authorization code redemptions that resulted in unexpected privilege escalation, particularly to admin-level roles or realm-management roles
    Affected if Event logs show authorization codes that were redeemed to obtain tokens with elevated privileges (admin, realm-management) that were not initiated by known administrator accounts
  5. Check for unauthorized admin sessions
    Review active admin sessions through the Keycloak admin console or by querying the sessions endpoint. Look for admin sessions originating from unexpected IP addresses, user agents, or created at unusual times
    Affected if Active admin sessions exist that cannot be attributed to known, authorized administrators in your organization

A user is affected if running any of the listed Keycloak versions (26.2, 26.2.15, 26.4, 26.4.11) AND unauthorized or forged authorization codes are present in the SingleUseObjectProvider store, or if admin sessions have been created through the bypassed authorization flow.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor patches when released; until then, implement network-level access controls and monitor for anomalous authorization code patterns. Review existing authorization code flows for signs of tampering.

Recommended fix Moderate confidence

Keycloak 26.4.x or later stable release as specified in Red Hat security advisory (confirm exact version from access.redhat.com)

  1. 1. Identify the exact Keycloak version currently deployed by checking the server startup logs or the about/version endpoint
  2. 2. Consult Red Hat's official security advisory for CVE-2026-4282 at access.redhat.com to confirm the specific fixed version number
  3. 3. Review the Keycloak 26.x release notes at keycloak.org to verify which version contains the fix for SingleUseObjectProvider type/namespace isolation
  4. 4. Before upgrading in production, test the new version in a staging environment to ensure compatibility with existing workflows and integrations
  5. 5. Perform a full backup of the Keycloak database and configuration
  6. 6. Upgrade Keycloak to the fixed version (26.4.x or later stable release as specified in the Red Hat advisory)
  7. 7. Verify the SingleUseObjectProvider behavior post-upgrade by monitoring authentication flows
  8. 8. Check Keycloak logs for any authorization code anomalies that might indicate attempted exploitation
Caveat Review Keycloak 26.x upgrade notes for potential breaking changes in authentication flows, user storage, or client configurations before migrating

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Build Of Keycloak Scoped from the published advisory
  • Consultation6.0 h
  • Implementation20.0 h
  • Testing12.0 h
  • Review / QA6.0 h
44.0 hours of engineering $7,680
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-4282 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data