An issue was discovered in Couchbase Server 5.x and 6.x before 6.5.2 and 6.6.x before 6.6.2. Internal users with administrator privileges, @cbq-engine-cbauth and @index-cbauth, leak credentials in cleartext in the indexer.log file when they make a /listCreateTokens, /listRebalanceTokens, or /listMetadataTokens call.