Nostalrius Begins - Quality wow vanilla realm (1.12)

As in the topic: a hunter is standing in the middle of a flare, is there any chance to sprint + sap or stun him before stealth breaks?

I managed to find some info that it was indeed possible, but it regarded different versions of WoW (later expansions)

Does the flare "pulse" just like concecration or is it active all the time? I'm just trying to find out if there is any chance to get an opener on a hunter standing on a flare.

I've done plenty of times. But most of the time it just fails.
Best learn some patience

If the hunters stands in the center of the flare, no, you will not be able to stun them through it. It doesn't pulse, it's always active.