CVE-2026-4349

A vulnerability was determined in Duende IdentityServer 4. 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. The vendor was contacted early about this disclosure but did not respond in any way.

CVSS v3 5.6 MEDIUM
CVSS v2.0 5.1 MEDIUM

5.6^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

5.1^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:H/Au:N/C:P/I:P/A:P

Exploitability : 4.9 / Impact : 6.4

Access Vector NETWORK

Access Complexity HIGH

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://vuldb.com/?ctiid.351380
https://vuldb.com/?id.351380
https://vuldb.com/?submit.772071

Configurations

No configuration.

History

18 Mar 2026, 14:52

Type	Values Removed	Values Added
Summary		(es) Se determinó una vulnerabilidad en Duende IdentityServer 4. El elemento afectado es una función desconocida del archivo /connect/authorize del componente Token Renewal Endpoint. Esta manipulación del argumento id_token_hint causa una autenticación impropia. Es posible iniciar el ataque de forma remota. El ataque se considera de alta complejidad. La explotabilidad se describe como difícil. El proveedor fue contactado tempranamente sobre esta divulgación, pero no respondió de ninguna manera.

17 Mar 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-17 22:16

Updated : 2026-03-18 14:52

NVD link : CVE-2026-4349

Mitre link : CVE-2026-4349

CVE.ORG link : CVE-2026-4349

JSON object : View

Products Affected

No product.

CWE

CWE-287

Improper Authentication

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