A flaw was found in the oauth-server component. This open redirect vulnerability occurs when the 'then' parameter in the grant approval handler is not properly validated. A remote attacker can craft a malicious URL that, when approved or denied by an authenticated user, redirects them to an attacker-controlled website. This could enable phishing attacks, potentially tricking users into revealing sensitive information.
There is no mitigation for this flaw. However, the risk is limited as the vulnerability only enables phishing — no OAuth tokens, authorization codes, or session credentials are exposed through the redirect.