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Findings

CVE-2026-4349

A vulnerability was determined in Duende IdentityServer4 up to 4.1.2.

Published Mar 17, 2026 · updated Jun 17, 2026

A vulnerability was determined in Duende IdentityServer4 up to 4.1.2. 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. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitability is described as difficult. This vulnerability only affects products that are no longer supported by the maintainer.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 17, 2026 · NIST NVD

    Detected

    A vulnerability was determined in Duende IdentityServer4 up to 4.1.2. 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. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitability is described as d

  2. Jun 17, 2026 · NIST NVD

    Updated

    A vulnerability was determined in Duende IdentityServer4 up to 4.1.2. 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. It is possible to initiate the attack remotely. The attack is considered to have high complexity. The exploitability is described as d

Sources

  • CVE.orgVulnerability recordCVE-2026-4349

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-4349

    A vulnerability was determined in Duende IdentityServer4 up to 4.1.2. 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. It is possible

    nvd.nist.gov

References