Exposure of Sensitive Information Through Metadata vulnerability in Apache ActiveMQ Broker, Apache ActiveMQ, Apache ActiveMQ All. Brokers that are configured with a network connector with syncDurableSubs set to true, are vulnerable to an unauthenticated attacker who can receive a list of all durable topic subscriptions in the broker, including client identifiers, subscription names, topic destinations, and JMS selector expressions, by sending a BrokerInfo command. The broker incorrectly responds without first ensuring the connection is authenticated. This issue affects Apache ActiveMQ Broker: before 5.19.7, from 6.0.0 before 6.2.6; Apache ActiveMQ: before 5.19.7, from 6.0.0 before 6.2.6; Apache ActiveMQ All: before 5.19.7, from 6.0.0 before 6.2.6. Users are recommended to upgrade to version 6.2.6 or 5.19.7, which fixes the issue.