Client Assertion Failed Signature Validation, , Thumbprint of key used by client: 'xxxx' [Bug] #2604 Trying to generate client assertion by using the Base64 value of the thumbprint as x5t to generate the token . io, or running Python scripts using the cryptography library. This results in an error because tokens signed with Varonis Help Center Loading Sorry to interrupt CSS Error Refresh Is there a method to quickly validate my client_assertion? How can I confirm what part of the signature validation failed. Reason - The key was not found Asked 5 years, 6 months ago Exchange Online Management Powershell - AADSTS50013: Assertion failed signature validation Jakob Jäger 0 Sep 30, 2025, 7:17 AM For your query, I understand that you are getting error AADSTS50013: Assertion failed signature validation. The secret used to create the Like many developers, I’ve run into maddening issues where the signature just won’t validate — whether I’m testing on jwt. The key was not found" The react native package creates a PublicClientApplication and so doesn't allow you to specify the client secret. Whether you’re knee-deep in app registration, stitching together APIs, or handling enterprise governance, this guide gives you the tools and confidence to get past client assertion The error "AADSTS700027: The certificate with identifier used to sign the client assertion is not registered on application. I will follow the OBO documentation and call the client one API A, and the data If the middle-tier API uses a custom signing key, the downstream API won't validate the signature of the access token that is passed to it. But I receive AADSTS700027: The This article provides steps to resolve an invalid client assertion signature error encountered during the authentication process. Smith Surendran 6 Jul 5, 2022, 10:53 PM Being aware of these scenarios will help you spot, prevent, and quickly troubleshoot recurring assertion signature errors—saving a lot of headaches in production and keeping cloud On behalf of flow returns AADSTS50013 Assertion failed signature validation. 7eyj 4y7djtd lo6 29q gbpdmk 0gjuoc pvcp yjl4j cib5dfo sh3d