@Loki: This is not a vulnerability within my JSON parser, but rather a vulnerability in how it is used. It would be no different than retrieving something like <span>sometext\r\n</span> (where \r\n is carriage-return linebreak) from a socket and not sanitizing it before sending it to the channel.
As far as the whole "ask the script author" comment. I understand we are here to help with mIRC and not scripts other's have wrote, but a quick look at the result, and the behavior described by the OP indicates not a problem with the linked 'tool' script, but rather something unexpected within mIRC happening.
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Anyways, my JSON parser does not sanitize messages. When items are queried they are returned as-is, with linebreaks and the such included. You will need to handle those before passing the data on, to say, a channel
