A flaw was found in the Keycloak LDAP User Federation provider. This vulnerability allows an authenticated realm administrator to trigger deserialization of untrusted Java objects via a malicious LDAP server configuration.
Weakness
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-operator-bundle:26.2.11-1 | * |
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-rhel9:26.2-12 | * |
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-rhel9-operator:26.2-12 | * |
| Red Hat build of Keycloak 26.2.11 | RedHat | keycloak | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-operator-bundle:26.4.6-1 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9:26.4-6 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9-operator:26.4-5 | * |
| Red Hat build of Keycloak 26.4.6 | RedHat | keycloak | * |
Potential Mitigations
- Make fields transient to protect them from deserialization.
- An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.
Related Attack Patterns
References
- https://access.redhat.com/errata/RHSA-2025:22088
- https://access.redhat.com/errata/RHSA-2025:22089
- https://access.redhat.com/errata/RHSA-2025:22090
- https://access.redhat.com/errata/RHSA-2025:22091
- https://access.redhat.com/security/cve/CVE-2025-13467
- https://bugzilla.redhat.com/show_bug.cgi?id=2416038
- https://github.com/keycloak/keycloak/commit/754c070cf8ca187dcc71f0f72ff3130ff2195328
- https://github.com/keycloak/keycloak/issues/44478