CVE-2026-46389
Summary
by MITRE • 06/05/2026
UDS Identity Config builds the Keycloak configuration image (realm, plugins, theme, truststore, JARs) consumed by UDS Core's Identity deployment. In versions 0.11.0 through 0.26.0, a logic error in the `client-kubernetes-secret` Keycloak client authenticator (shipped by `uds-identity-config` and consumed by UDS Core) causes the submitted `client_secret` to be overwritten with the mounted Kubernetes secret before comparison. An attacker who can reach the Keycloak token endpoint and knows a `client_id` using this authenticator can authenticate as that client with any `client_secret` value and obtain OAuth2 tokens scoped to the client's service account. In the case of the `uds-operator` client this token can be used to registry/modify other clients. Version 0.26.1 patches the issue.
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Analysis
by VulDB Data Team • 06/05/2026
The vulnerability described represents a critical authentication bypass flaw in the UDS Identity Configuration component that affects versions 0.11.0 through 0.26.0. This issue stems from a fundamental logic error within the `client-kubernetes-secret` Keycloak client authenticator implementation, which is a core component of the identity management infrastructure. The authenticator is designed to validate client credentials by comparing submitted secrets against stored values, but due to the flawed implementation, it inadvertently overwrites the provided client_secret with the contents of a mounted Kubernetes secret before performing any comparison operation.
The technical execution of this vulnerability occurs at the OAuth2 token endpoint where authentication requests are processed. When an attacker submits a valid client_id to the Keycloak token endpoint while using the affected authenticator, the system's flawed logic causes it to replace the submitted client_secret value with the Kubernetes secret content before conducting the authentication comparison. This logic error effectively nullifies the security mechanism designed to verify client credentials, allowing any attacker who can reach the token endpoint and knows a valid client_id to authenticate successfully regardless of the client_secret they provide. The vulnerability specifically impacts the authentication flow for Keycloak clients that utilize the `client-kubernetes-secret` authenticator, which is a standard mechanism for integrating Kubernetes secrets with Keycloak client authentication.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to obtain OAuth2 tokens with service account scopes that grant elevated privileges. When the vulnerable authenticator is used with the `uds-operator` client, the resulting tokens can be leveraged to perform registry and modification operations on other clients within the system. This creates a severe privilege escalation scenario where an attacker can manipulate the entire client configuration landscape, potentially compromising the integrity and confidentiality of the identity management system. The vulnerability essentially provides attackers with a backdoor mechanism to bypass authentication controls and gain administrative access to client configurations, making it particularly dangerous in environments where service account tokens are used for critical operations.
This vulnerability aligns with CWE-287 (Improper Authentication) and represents a classic case of authentication bypass through flawed credential validation logic. The issue also maps to ATT&CK technique T1566.002 (Phishing: Spearphishing Attachment) in scenarios where attackers might leverage the compromised client authentication to establish persistent access or move laterally within the system. The root cause of this flaw demonstrates poor input validation and authentication flow implementation, where the system should have compared the submitted credentials against the stored values without modifying the submitted data during the validation process. Organizations using affected versions should immediately upgrade to version 0.26.1 or later to remediate this vulnerability, as the patch addresses the core logic error in the authenticator implementation that was allowing the client_secret to be overwritten before comparison. The fix ensures that submitted credentials are properly validated against stored values without being modified during the authentication process, restoring the intended security controls for client authentication.