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CVE-2026-70665

Doorkeeper OpenID Connect: DCR endpoint persists unvalidated client-supplied scopes

Published: Aug 25, 2026Updated: Aug 27, 2026 Sources: CVE List NVDCWE-285
4.2MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 94.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

Description

Doorkeeper OpenID Connect implements an OpenID Connect authentication provider for Rails applications on top of Doorkeeper. Prior to 1.10.4, the Dynamic Client Registration (DCR) endpoint persists client-supplied scopes without validating them against the server's configured scope set. Under certain conditions, this allows a self-registered client to obtain scopes beyond what the server intended to grant. In DynamicClientRegistrationController#application_params, the scopes attribute is assigned directly from params[:scope] with no validation against Doorkeeper.configuration.scopes or optional_scopes. Combined with enforce_configured_scopes being off by default and Doorkeeper's ScopeChecker prioritizing application-level scopes over server-level scopes, this creates a privilege escalation path. This issue is fixed in version 1.10.4.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:RS:UC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-285

Affected Products

doorkeeper-gem
package-ecosystemaka doorkeeper
doorkeeper-openid_connectLibrary
OSS Libraries / rubygems

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://github.com/doorkeeper-gem/doorkeeper-openid_connect/security/advisories/GHSA-8r7r-wh7x-27ff
github.com
https://github.com/doorkeeper-gem/doorkeeper-openid_connect/commit/24c3cb1729b69f48649a6f4491dcae69f805000d
github.com

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