HashiCorp Consul and Consul Enterprise 1.4.1 through 1.6.2 did not uniformly enforce ACLs across all API endpoints, resulting in potential unintended information disclosure. Fixed in 1.6.3.
HashiCorp Consul 1.4.0 through 1.5.0 has Incorrect Access Control. Keys not matching a specific ACL rule used for prefix matching in a policy can be deleted by a token using that policy even with default deny settings configured.
HashiCorp Consul 1.4.3 lacks server hostname verification for agent-to-agent TLS communication. In other words, the product behaves as if verify_server_hostname were set to false, even when it is actually set to true. This is fixed in 1.4.4.
HashiCorp Consul (and Consul Enterprise) 1.4.x before 1.4.3 allows a client to bypass intended access restrictions and obtain the privileges of one other arbitrary token within secondary datacenters, because a token with literally "<hidden>" as its secret is used in unusual circumstances.
HashiCorp Consul 0.5.1 through 1.4.0 can use cleartext agent-to-agent RPC communication because the verify_outgoing setting is improperly documented. NOTE: the vendor has provided reconfiguration steps that do not require a software upgrade.