CVE-2019-9837

Doorkeeper::OpenidConnect (aka the OpenID Connect extension for Doorkeeper) 1.4.x and 1.5.x before 1.5.4 has an open redirect via the redirect_uri field in an OAuth authorization request (that results in an error response) with the ‘openid’ scope and a prompt=none value. This allows phishing attacks against the authorization flow.
Source: NIST