mIRC v6.12 has been released to address a remote vulnerability found yesterday, capable of crashing your mIRC. The vulnerability affects versions of mIRC from v6.0 onwards, so it is highly recommended that you upgrade to mIRC v6.12:

Update: Thanks to Mr A looks like we've found a fresh bug in mIRC v6.12 ... Read More well it's me another time... just installing 6.12 i found a big bug in mirc 6.12

it sems that making a whois to some user with lots of channels like some bots.. make a buffer overflow .. this can be explotable easy.

mIRC.com or mIRC.co.uk