Auth0 Support Center - "502 Bad Gateway" Error Received after Configuring a Reverse Proxy to Communicate with Auth0

"502 Bad Gateway" Error Received after Configuring a Reverse Proxy to Communicate with Auth0

Sep 10, 2025

Overview

A 502 Bad Gateway error is seen during the login process after configuring a reverse proxy to communicate with Auth0. The vendor confirms that the reverse proxy requests are being sent to the origin domain name.

Applies To

Self-managed custom domain
Reverse Proxy

Cause

This issue is caused by a misconfiguration on the reverse proxy. Usually, in this situation, the request does not reach Auth0, so check with the vendor that is used to troubleshoot the issue.

Solution

Confirm that this 502 error message is coming from the reverse proxy by gathering a HAR file of the reproduction. The response header from this 502 error message will contain the server.