What is Vuln?
1.
An abbreviation of the word vulnerable. Used primarily in 'internet speak'. Normally used when speaking about weak spots in an opponents skills or strategies in a game or in weak spots in computer code that a hacker exploits.
I am not sure I want to install Internet Explorer 8 yet; I heard there are a lot of vulns that need patched.
or
His vuln is that he has low fire resist so make sure you use fire damage against him.
See