Keycloak OIDC Broker Email-Verified Claim Bypass
CVE-2026-14781 Published on July 5, 2026
Keycloak-services: keycloak-services: oidc email_verified claim incorrectly applied to userinfo email
A flaw exists in the org.keycloak.broker.oidc package where the OIDC broker incorrectly synchronizes the email_verified claim. When an OIDC identity provider is configured with trustEmail=true and the userinfo endpoint is enabled, Keycloak retrieves the email address from the userinfo response but retrieves the email_verified status exclusively from the id_token.
The root cause is a lack of validation ensuring that the email_verified claim in the id_token actually refers to the email address returned by the userinfo endpoint. If these two sources return different email addresses, the id_token's email_verified=true claim is blindly applied to the userinfo email.
Exploitation Conditions:
The OIDC identity provider must have trustEmail set to true (non-default).
The userinfo endpoint must be enabled (default).
The attacker must control or have compromised the upstream OIDC provider.
Concrete Impact:
Mark arbitrary email addresses as verified in the Keycloak database.
Bypass email-based security controls or verification workflows.
Potential account takeover if the application relies solely on the email_verified flag from the IdP to link accounts.
Vulnerability Analysis
CVE-2026-14781 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public. 3 days later.
Weakness Type
Improper Validation of Consistency within Input
The product receives a complex input with multiple elements or fields that must be consistent with each other, but it does not validate or incorrectly validates that the input is actually consistent.
Products Associated with CVE-2026-14781
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