ColdFusion Server 5 (And Previous Versions): Client Variable Size Limit of 65,000 Characters
Macromedia ColdFusion Server versions 5 and earlier have a hard-coded limit of 65,000 characters per client for client variables. Although customers may create client variables greater than 65,000 characters in size, ColdFusion will only be able to store and retrieve 65,000 characters for client variables on ColdFusion pages. (Please note that there is no such limit in ColdFusion MX.)
ColdFusion Server 5 (And Previous Versions): Client Variable Size Limit of 65,000 Characters