RHSA-2025:4336
Vulnerability from csaf_redhat - Published: 2025-04-29 22:53 - Updated: 2026-04-01 13:31Summary
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.
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)
Vendor Fix
Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.
https://access.redhat.com/errata/RHSA-2025:4336
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)
Vendor Fix
Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.
https://access.redhat.com/errata/RHSA-2025:4336
Workaround
Use the correct TLS configuration and avoid using "--tls-hostname-verifier=any".
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)
Vendor Fix
Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on.
https://access.redhat.com/errata/RHSA-2025:4336
Workaround
No current mitigations are available for this vulnerability.
References
Acknowledgments
Red Hat
Marek Posolda
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- 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.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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