A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.
Weakness
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-operator-bundle:26.4.10-1 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9:26.4-12 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9-operator:26.4-12 | * |
| Red Hat build of Keycloak 26.4.10 | RedHat | rhbk/keycloak-rhel9 | * |