I think dareness is not the word, since it doesn't appear in Thesaurus. What the common noun? Example sentence:
The woman suddenly kissed the man. That put him into a __-induced stupor.
Daringness (or just daring) would be the noun forms you're looking for, but you might try "boldness" instead.
Something is daring if it's boldly assertive in nature. A person can be daring, and a person's actions can be described as daring, but you can't say "X is affected by something being boldly assertive" with anything derived from dare.
By might save the day here, and while stupor induced by daring will not work (because it's not clear whose daring), stupor induced by her daring would. It will sound rather "deadpan" unless you can put an adjective in front of stupor:
The woman suddenly kissed the man. That put him into a swooning stupor induced by her daring.
This would sound better:
The woman suddenly kissed the man, him then being induced to stupor by her daring.
It's not really clear if you intent the woman's kiss to make the man stronger (daring) or weaker (stupor)?
But, the word you may be looking for is
The woman's sudden kiss emboldened him to kiss her back.
Unless you do really mean
in which case
The woman's sudden kiss caused him to melt and become weak-kneeded.