CVE-2026-4349 | Duende IdentityServer4 up to 4.1.2 Token Renewal Endpoint /connect/authorize id_token_hint improper authentication
A vulnerability was found in Duende IdentityServer4 up to 4.1.2. It has been rated as critical. The affected element is an unknown function of the file /connect/authorize of the component Token Renewal Endpoint. This manipulation of the argument id_token_hint causes improper authentication. This vulnerability only affects products that are no longer supported by the maintainer.
The identification of this vulnerability is CVE-2026-4349. It is possible to initiate the attack remotely. There is no exploit available.