Duende IdentityServer4 Token Renewal Endpoint authorize improper authentication
Summary
| CVE | CVE-2026-4349 |
|---|---|
| State | PUBLISHED |
| Assigner | VulDB |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-03-17 22:16:15 UTC |
| Updated | 2026-04-22 21:32:08 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 6.3 MEDIUM from [email protected]
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.000300000 probability, percentile 0.087020000 (date 2026-04-22)
Problem Types: CWE-287 | CWE-287 Improper Authentication
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | DECLARED | 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 |
| 3.1 | [email protected] | Secondary | 5.6 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | CNA | DECLARED | 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 |
| 3.0 | CNA | DECLARED | 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 |
| 2.0 | [email protected] | Secondary | 5.1 | AV:N/AC:H/Au:N/C:P/I:P/A:P | |
| 2.0 | CNA | DECLARED | 5.1 | AV:N/AC:H/Au:N/C:P/I:P/A:P/E:ND/RL:ND/RC:ND |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
CVSS v3.0 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
LowCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:X/RC:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Duende | IdentityServer4 | affected 4.1.0 | Not specified |
| CNA | Duende | IdentityServer4 | affected 4.1.1 | Not specified |
| CNA | Duende | IdentityServer4 | affected 4.1.2 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| vuldb.com | [email protected] | vuldb.com | |
| vuldb.com | [email protected] | vuldb.com | |
| vuldb.com | [email protected] | vuldb.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Edcarlos (VulDB User) (en)
CNA: VulDB (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-17T00:00:00.000Z | Advisory disclosed |
| CNA | 2026-03-17T01:00:00.000Z | VulDB entry created |
| CNA | 2026-03-25T12:00:53.000Z | VulDB entry last update |
There are currently no legacy QID mappings associated with this CVE.