The vulnerability exists in Apache Solr’s RuleBasedAuthorizationPlugin where insufficiently strict input validation allows users to bypass certain predefined permission rules and access Solr APIs such as configuration reading, configuration editing, schema reading, metrics reading, or security reading. This can lead to unauthorized manipulation or disclosure of configuration, schema, and monitoring data, compromising the confidentiality and integrity of the Solr instance. Only deployments that satisfy all of the following: use of RuleBasedAuthorizationPlugin, a configuration specifying multiple roles, a permission list containing one or more of the listed predefined rules, no "all" permission, and an open network path for client requests, are affected.

Deployments of Apache Solr versions 5.3.0 through 9.10.0 distributed by the Apache Software Foundation, when the RuleBasedAuthorizationPlugin is enabled with multiple roles and the described permission set, are impacted.

The CVSS score of 8.2 indicates high severity, while the EPSS score of less than 1% and absence from the KEV catalog suggest a low likelihood of exploitation at present. The event likely involves an attacker sending unfiltered HTTP or HTTPS requests directly to the Solr endpoint; due to the plugin’s validation flaw the attacker can then gain unauthorized access to sensitive APIs. The impact is limited to affected deployments where the described conditions hold true.