Auth0 SAML Errors Occur When the Service Provider Requires Signed Assertions and Responses

Last Updated: Aug 5, 2026

Overview

Security Assertion Markup Language (SAML) errors occur when using Auth0 as the Identity Provider (IdP), and a third-party Service Provider (SP) requires signed assertions and responses. These errors occur because Auth0 does not support signing both the assertion and the response simultaneously. To resolve this, submit a feature request to prioritize adding this functionality. An attempt to sign in fails with the following error:

SAML Response not signed

After updating the configuration to sign the response, a subsequent login attempt fails with a second error:

SAML assertion not signed

Applies To

Auth0
Security Assertion Markup Language (SAML)
Identity Provider (IdP)

Cause

The errors occur because the SP requires signed SAML assertions and responses. Auth0 does not support signing both the assertion and the response simultaneously when acting as the IdP.

Solution

Why do SAML errors occur when the SP requires signed assertions and responses?

Auth0 does not support signing both the SAML assertion and response when acting as the IdP. An item to add this functionality exists in the product feature backlog. Submit a feature request via the Customer Feedback form to help prioritize this feature.