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6 CVEs HIGH CVSS 7.5

Keycloak Authentication and Authorization Flaws

2026-05-28

CVE-2026-9793 HIGH

Signature verification bypass in Red Hat Build of Keycloak exposes OIDC authorization flows to unauthorized claim injection via JWE-encrypted request objects. When a JWE-encrypted request object is submitted and its decrypted payload is raw JSON rather than a signed JWT, Keycloak processes the claims without enforcing the configured signature policy, violating both OIDC Core and Financial-grade API (FAPI) signing requirements. An unauthenticated remote attacker can exploit this to submit forged claims into the authorization flow, achieving high integrity impact against affected deployments; no public exploit has been identified at time of analysis, and a redirect URI allowlist serves as a partial compensating control.

7.5
CVSS
0.0%
EPSS
CVE-2026-9795 HIGH PATCH

Privilege escalation in Keycloak's Fine-Grained Admin Permissions v2 (FGAPv2) allows an administrator with only limited client-management rights to attach arbitrary realm roles - including highly privileged ones - to a client's scope mappings, causing those roles to be injected into user authentication tokens that traverse the modified client. The flaw affects the Red Hat Build of Keycloak per the vendor advisory and has no public exploit identified at time of analysis, but the high-privilege admin pivot makes it operationally significant in multi-tenant identity deployments.

7.3
CVSS
0.0%
EPSS
CVE-2026-9792 MEDIUM PATCH

Policy enforcement bypass in Red Hat Build of Keycloak's Client Policies framework allows unauthenticated remote attackers to obtain OAuth2 tokens via the Resource Owner Password Credentials (ROPC) grant even when an explicit `reject-ropc-grant` executor is configured to block it. The bypass is triggered specifically when certain condition providers - client-type, client-roles, client-attributes, or client-scopes - are used within the same policy, causing silent executor skipping rather than a fail-closed enforcement error. Successful exploitation results in unauthorized token issuance and potential information disclosure. No public exploit code and no CISA KEV listing have been identified at time of analysis.

6.5
CVSS
0.0%
EPSS
CVE-2026-9796 MEDIUM PATCH

Privilege escalation in Red Hat Build of Keycloak allows an authenticated administrator holding the manage-clients role to exploit a Time-of-check to time-of-use (TOCTOU) race condition in name-based admin role checks, elevating their privileges to realm-admin for all users within the realm. The resulting composite role relationship is persistent - it survives both manual revocation of the attacker's original permissions and system reboots, making remediation non-trivial post-exploitation. No public exploit code has been identified at time of analysis, and this CVE is not listed in the CISA KEV catalog.

6.5
CVSS
0.0%
EPSS
CVE-2026-9794 MEDIUM PATCH

Information disclosure in Red Hat Build of Keycloak exposes client protocol type to unauthenticated remote attackers via error message enumeration. By submitting specially crafted SOAP requests targeting the SAML ECP (Enhanced Client or Proxy) endpoint with varying client IDs, an attacker can observe distinct faultstring values in server responses and map which clients use which protocol types. No authentication, user interaction, or elevated privileges are required, and the CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms exploitation is straightforward against any exposed instance. No public exploit code has been identified and this CVE is not listed in the CISA KEV catalog at time of analysis.

5.3
CVSS
0.0%
EPSS
CVE-2026-9791 MEDIUM PATCH

Incorrect authorization enforcement in Red Hat Build of Keycloak allows an authenticated user with existing organization membership to retrieve organization metadata through the account API or via OIDC token requests using the 'organization' scope, even when an administrator has explicitly disabled the Organizations feature. The flaw (CWE-863) means the feature-disabled state is not enforced at the data-access layer, so tokens and API responses continue to carry organization claims. This can cause downstream resource servers that consume those tokens to make incorrect authorization decisions - for example, granting access based on organizational membership that should no longer be recognized. No public exploit code exists and this vulnerability is not listed in CISA KEV at time of analysis.

4.3
CVSS
0.0%
EPSS

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