RHSA-2025:4336

Vulnerability from csaf_redhat - Published: 2025-04-29 22:53 - Updated: 2026-05-06 16:52
Summary
Red Hat Security Advisory: Red Hat build of Keycloak 26.0.11 Update
Severity
Important
Notes
Topic: New Red Hat build of Keycloak 26.0.11 packages are available from the Customer Portal
Details: Red Hat build of Keycloak 26.0.11 is a standalone server, based on the Keycloak project, that provides authentication and standards-based single sign-on capabilities for web and mobile applications. Security fixes: * JWT Token Cache Exhaustion Leading to Denial of Service (DoS) in Keycloak * Keycloak hostname verification * Two factor authentication bypass
Terms of Use: This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Red Hat Inc. and provide a link to the original.
CVE-2025-2559

A flaw was found in Keycloak. When the configuration uses JWT tokens for authentication, the tokens are cached until expiration. If a client uses JWT tokens with an excessively long expiration time, for example, 24 or 48 hours, the cache can grow indefinitely, leading to an OutOfMemoryError. This issue could result in a denial of service condition, preventing legitimate users from accessing the system.

4.9 (Medium)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE-770 - Allocation of Resources Without Limits or Throttling
Affected products
Product Identifier Version Remediation
Red Hat Build of Keycloak
Red Hat / Red Hat build of Keycloak
 cpe:/a:redhat:build_keycloak:26 —
Vendor Fix fix
Threats
Impact Moderate
CVE-2025-3501

A flaw was found in Keycloak. By setting a verification policy to 'ALL', the trust store certificate verification is skipped, which is unintended.

8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
CWE-297 - Improper Validation of Certificate with Host Mismatch
Affected products
Product Identifier Version Remediation
Red Hat Build of Keycloak
Red Hat / Red Hat build of Keycloak
 cpe:/a:redhat:build_keycloak:26 —
Vendor Fix fix
Workaround
Threats
Impact Important
CVE-2025-3910

A flaw was found in Keycloak. The org.keycloak.authorization package may be vulnerable to circumventing required actions, allowing users to circumvent requirements such as setting up two-factor authentication.

5.4 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CWE-287 - Improper Authentication
Affected products
Product Identifier Version Remediation
Red Hat Build of Keycloak
Red Hat / Red Hat build of Keycloak
 cpe:/a:redhat:build_keycloak:26 —
Vendor Fix fix
Workaround
Threats
Impact Moderate
References
Acknowledgments
Red Hat Marek Posolda
To clipboard 

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      ],
      "title": "org.keycloak.authentication: Two factor authentication bypass"
    }
  ]
}


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Sightings

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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