CVE-2026-9795: Keycloak: keycloak: privilege escalation via improper scope mapping enforcement

Synopsis

This is a privilege escalation vulnerability in Keycloak's Fine-Grained Admin Permissions v2 (FGAPv2) feature. An authenticated administrator with limited client management rights can assign any realm role, including highly privileged ones, to a client's scope mapping, bypassing intended access controls. If a user then authenticates through the modified client, the injected role appears in their token, granting them privileges they were never intended to hold. No fix version has been published yet; HarborGuard tracks the advisory and will make a patched-image rebuild available the moment upstream ships a fix.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The Keycloak admin console must be reachable over the network; the attacker sends the malicious scope-mapping request from a remote client.

• AuthenticationRequired

  The attacker must hold an existing admin account with at least limited client management permissions; a fully unprivileged account is not sufficient.

• Victim interactionRequired

  A legitimate user must authenticate through the modified client for the injected role to be projected into their token, requiring that user to take a normal login action.

• Attack complexityDetail

  Attack complexity is high, meaning the attacker must navigate specific conditions around FGAPv2 permission boundaries and timing to successfully inject the scope mapping without detection.

Blast Radius

• A user authenticating through the tampered client receives a token carrying highly privileged realm roles they were never assigned, giving them administrative or elevated access within the Keycloak realm.
• The injected role can be used downstream by any service that trusts Keycloak-issued tokens, propagating the privilege escalation beyond the identity layer into protected APIs and applications.
• Realm-level security boundaries set by the Keycloak administrator are silently bypassed, meaning audit logs may show normal logins while the underlying permissions are inflated.