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

Opster Team

August-23, Version: 7.16-8.9

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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.

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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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