Describe CVE-2020-26938.
What is CVE-2020-26938?
In oauth2-server (aka node-oauth2-server) through 3.1.1, the value of the redirect_uri parameter received during the authorization and token request is checked against an incorrect URI pattern ("[a-zA-Z][a-zA-Z0-9+.-]+:") before making a redirection. This allows a malicious client to pass an XSS payload through the redirect_uri parameter while making an authorization request. NOTE: this vulnerability is similar to CVE-2020-7741..