CVE-2026-4349 (GCVE-0-2026-4349)

Vulnerability from cvelistv5 – Published: 2026-03-17 21:32 – Updated: 2026-03-25 10:56 Unsupported When Assigned
VLAI?
Title
Duende IdentityServer4 Token Renewal Endpoint authorize improper authentication
Summary
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.
Severity ?
6.3 (Medium)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
5.6 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X
5.6 (Medium)
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X
CWE
  • CWE-287 - Improper Authentication
Assigner
References
https://vuldb.com/?id.351380 vdb-entrytechnical-description
https://vuldb.com/?ctiid.351380 signaturepermissions-required
https://vuldb.com/?submit.772071 third-party-advisory
Impacted products
Vendor Product Version
Duende IdentityServer4 Affected: 4.1.0
Affected: 4.1.1
Affected: 4.1.2
Create a notification for this product.
Credits
Edcarlos (VulDB User) VulDB
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.