A flaw was found in Keycloak's Dynamic Client...
High severity
Unreviewed
Published
Aug 5, 2026
to the GitHub Advisory Database
Description
Published by the National Vulnerability Database
Aug 5, 2026
Published to the GitHub Advisory Database
Aug 5, 2026
A flaw was found in Keycloak's Dynamic Client Registration (DCR) security policy management. The "Allowed Protocol Mapper Types" policy, which restricts which types of data mappers a client can use, fails to re-validate the mapper type during a client update if the mapper's configuration remains unchanged. An attacker with client registration privileges can exploit this by first registering an allowed mapper type with a malicious configuration and then swapping it for a restricted, high-privilege mapper type (such as one that hardcodes administrative roles). This allows the attacker to gain full administrative access to the Keycloak realm.
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