Authentication token must present for realms authentication – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.16-8.9

Briefly, this error occurs when Elasticsearch is unable to authenticate a user because an authentication token is missing. This usually happens when a user tries to access Elasticsearch’s secured resources without providing valid credentials. To resolve this issue, ensure that you’re sending a valid authentication token in your requests. If you’re using an API, make sure the token is included in the header. If you’re using a client, ensure the client is properly configured to send the token. Also, check your Elasticsearch security settings to ensure that the realm is correctly configured to accept the token.

This guide will help you check for common problems that cause the log ” authentication token must present for realms authentication ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “authentication token must present for realms authentication” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 public void authenticate(Context context; ActionListener> listener) {
 if (context.getMostRecentAuthenticationToken() == null) {
 new ElasticsearchSecurityException("authentication token must present for realms authentication"; RestStatus.UNAUTHORIZED)
 assert context.getMostRecentAuthenticationToken() != null : "null token should be handled by fallback authenticator";
 consumeToken(context; listener);


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