The vulnerability arises when the Apache Solr BasicAuth bootstrap tool (bin/solr auth enable) silently creates hard‑coded template users (superadmin, admin, search, index) with known default credentials. An attacker who learns these credentials gains unrestricted administrative control over the Solr cluster, enabling configuration changes, data exfiltration, and service disruption. This flaw falls under insecure default configuration weaknesses (CWE-1188) and hard‑coded passwords (CWE-798).

Apache Solr versions 9.4.0 through 9.10.1 and 10.0.0 are affected. Clusters that never used the bin/solr auth enable command during bootstrap or that have replaced the template users with strong, unique passwords are not vulnerable.

The CVSS score of 8.1 indicates high severity, and the EPSS score of 4% suggests a modest exploitation probability. The vulnerability allows an attacker who obtains the hard‑coded default credentials installed by the bin/solr auth enable tool to log in as a full administrator. From there, the attacker can use authenticated requests to the Solr cluster to view, modify, or delete configuration settings, data, and other resources. Authentication is performed over the network, so a remote threat actor with network reach to the cluster could simply use the known default credentials to gain unrestricted control. The vulnerability is not listed in the KEV catalog but remains a significant risk due to the ease of exploitation once the default credentials exist.