You bet it's a safety issue! And it was last year as well. Anything that burns burns wood and many other fuels produces CO and particulate matter. Allowing this to vent into the interior is a receipe for disaster. CO is odorless and invisible. Many people die every winter from its effects because of improperly vented heating appliances. Particulate matter is not a good thing to have accumulate in your lungs, which is exactly what happens when you allow smoke to accumulate indoors. BTW, no code would permit the sort of set up you have/had.

Code here is strict, I must have misidentified the type, it's an airtight wood stove. No smoke indoors.

Get a CO2 detector. If it does not complain, then I suppose you have nothing to worry about.

An "airtight" woodstove still produces smoke, soot, creosote, and CO. If it is not vented into a chimney where does the smoke go? Believe me, no code, strict or otherwise, would permit the installation of any sort of wood burning stove without a connection to a chimney approved for use with a solid fuel appliance.

Never mind a CO detector. What you have is an inherently dangerous set up with a very great deal to worry about, assuming you're actually using this stove without a chimney, something I continue to find incomprehensible. You do seem to be dangerously uninformed/misinformed about a great many things, including what's meant by the term "airtight wood stove." Sorry to be harsh, but your life and the lives of anyone else present in the cabin are at stake any time you build a fire with no chimney connection.

If your inquiry is actually about providing a system for bringing in fresh air from the outside to support combustion, it may be necessary in such a small space if it is now tightly insulated. This is easily done and there are instructions for doing this available online.

A woodstove with no chimney? Why would anybody think that's OK?

I certainly HOPE what the original poster was saying is that he has no combustion air vent to bring in fresh air from outside. A stove with no chimney would fill the place up with smoke within minutes if not sooner.

Yes, there is a chimney! Otherwise it wouldn't have passed inspection. And my place would have burned down the first use... or I would be dead from smoke inhalation.
Why can't you edit on this site?

If that's the correct wording "combustion air vent", yes the approx 2" tin pipe from outdoors into the back or bottom of woodstove so that the stove is burning fresh air not house air.

I read the manual last night and unless I missed it (will read again) it doesn't mention this combustion air vent.
Not mentioned in index either.

This is a Jotul woodstove, well known decent brand. Maybe some of the newer stoves like this don't need combustion air vents? Doesn't make sense to me. Will call the dealer today.

Jotul sells Outside Air Kits for their stoves, including the Model 603 which is the most likely to be used in such a small area. If this is a post-1994 EPA Jotul it is unlikely to draft well at all in a tight well insulated space without an outside air source. Newer stoves need this more rather than less than the pre 1994 ones because of their restricted draft. On the other hand, if the stove is lightly used opening a window slightly may be sufficient.