VEXID-9283302
Published 2026-08-25 23:17:04
Last Modified 2026-08-25 23:17:04
AKA CVE-2026-44476
Summary Doorkeeper is an OAuth 2 provider for Ruby on Rails. In version 1.9.0, an attacker who knows only a dynamically registered client's client_id, which is public information, can authenticate as that client at the token endpoint and obtain an access token without providing its client_secret. This occurs because the Dynamic Client Registration feature creates applications with confidential: false hard-coded, even though the registration response returns a client_secret and advertises support for the client_secret_basic and client_secret_post authentication methods; since Doorkeeper treats a blank or missing secret as valid for non-confidential (public) clients, the secret is never verified. Only projects that have explicitly enabled Dynamic Client Registration, which is disabled by default, are affected. This issue is fixed in version 1.10.0.
CVSS
Access Vector Local Adjacent Network
Access Complexity Low Medium High
Authentication None Single Multiple
Confidentiality None Partial Complete
Integrity None Partial Complete
Availability None Partial Complete