Elasticsearch generally filters out sensitive information and credentials before logging to the audit log. It was found that this filtering was not applied when requests to Elasticsearch use certain deprecated _xpack/security URIs for APIs. The impact of this flaw is that sensitive information, such as passwords and tokens, might be printed in cleartext in Elasticsearch audit logs. Note that audit logging is disabled by default and needs to be explicitly enabled. Even when audit logging is enabled, request bodies that could contain sensitive information are not printed to the audit log unless explicitly configured.

The issue is resolved in Elasticsearch 8.9.2.

For more information, see our related security announcement.