An Open Redirect vulnerability exists in the OAuth callback handler in file onlook/apps/web/client/src/app/auth/callback/route.ts in Onlook web application 0.2.32. The vulnerability occurs because the application trusts the X-Forwarded-Host header value without proper validation when constructing a redirect URL. A remote attacker can send a manipulated X-Forwarded-Host header to redirect an authenticated user to an arbitrary external website under their control, which can be exploited for phishing attacks.